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Ruan Mei Full Guide ❀

Updated for 2.0; Written by sealary and mr.swedishfish, Edited by m4raku, and euphriia, Calculations provided by agentyoda, m4raku, drachk, and sealary

"Humans overestimate the infallibility of logic, and in clinging to reason can become slaves to their emotions. Science is born from fanaticism — it is a gift."

ruanmei

Guide Updates (Patch 2.0)

The following are the newest additions and changes to our guide with the release of patch 2.0.

New Relic Set: Watchmaker, Master of Dream Machinations

watchmaker This new relic set not only increases Break Effect for Ruan Mei by a hefty amount, it also increases Break Effect for the entire team. Due to this new Break Effect-focused relic set, many may wonder if making the switch to this set is necessary for Ruan Mei. Find out what set is right for you by checking out our updated 4PC Relic Set Recommendations for Ruan Mei!

New Light Cone: Earthly Escapade

sparklelc With the release of Sparkle, the newest and second limited Harmony character, comes a new 5-star light cone. How does this light cone compare to other existing options? Is it better than Bronya's light cone? Maybe even Meshing Cogs? Is it worth pulling if you've missed Ruan Mei's last light cone banner? Find out by checking out our updated Light Cone Recommendations for Ruan Mei!

Updated Synergy and Anti-Synergies

misha Misha joins the growing number of Ice DPS characters following the patch 2.0 update. Because of the Penacony, Land of Dreams relic set, which encourages the usage of Ice DPS characters with Ruan Mei, and his rarity, Misha is a potential budget option to use with Ruan Mei. His ultimate, which freezes enemies, pairs well with Ruan Mei's weakness break extension, causing enemy actions to be further delayed. With Misha's freeze and Ruan Mei's delay, enemies won't even have a chance to act! Read more about Ruan Mei's best and not-as-great teammates in our Teammates Section.

Seele has been added to the list of anti-synergies with Ruan Mei due to the fact that Ruan Mei can "steal" Seele's kills, preventing her from triggering her Resurgence passive. However, Ruan Mei is still a top pick for Seele due to her universal buffs.

Introduction

Ruan Mei is a 5-star Ice Harmony character and Member #81 of the Genius Society. As the first-ever limited 5-star Harmony character, Ruan Mei faces high expectations. These expectations especially concern her performance in relation to other high-value Harmony characters, such as Tingyun, Bronya, and Asta, as well as her overall utility and usage. Does she hold a candle to them, or is she outshined by their incredible support value? Read this guide to learn how to optimize Ruan Mei effectively, find out her best builds, and see how she can fit into your teams!

ruanmei

Ruan Mei TLDR

Ruan Mei is a support character capable of increasing allies' Weakness Break Efficiency, SPD, and All-Type RES PEN(1). At the same time, Ruan Mei can also deal additional Break DMG whenever allies Weakness Break an enemy, causing the Weakness Broken enemies' actions to be further delayed.

  1. RES PEN is short for resistance penetration. What is RES PEN and how does it work? Check out the Trace Overview section and read more about it in her Ultimate description!

If you need a quick overview on Ruan Mei and how to build her, you can check the infographic below or check our Quick Guide.

infographic

Infographic designed by littlemari

Pros and Cons

Why should you use and build Ruan Mei? Should you pull for Ruan Mei over other units? While she is admittedly high-cost for the average player as a limited 5-star character, she still provides a lot of utility as a strong support character. She certainly lives up to the daunting title of the first limited Harmony character, especially shining with her All-Type RES PEN, full-team buffs, and the fact that she's SP positive(1). However, she is not an absolute must-pull, so ultimately the choice is yours to make based on your own personal needs and opinions.

  1. SP positive, or skill point positive, refers to when a character generates more skill points than uses them. Ruan Mei is considered SP positive because her skill, which uses one skill point, lasts for three turns. This means that two out of three of her turns will be basic attacks, generating a net positive amount of skill points for her team.

clap

  • Ruan Mei's ultimate provides All-Type RES PEN, which is very valuable
  • Ruan Mei functions as a highly flexible team-wide support character
  • As a universal buffer, Ruan Mei will likely remain a strong character even in the future
  • Ruan Mei is SP positive
  • Ruan Mei is super pretty!

sigh

  • Ruan Mei is a limited 5-star character, so she's not as easily accessible as other characters
  • Ruan Mei doesn't replace existing Harmony characters who are already considered very good
  • Ruan Mei is not a "must pull" for your account

Playstyle Strategy

Because Ruan Mei is SP positive and her skill lasts for three turns, it is recommended to follow a Skill > Basic > Basic playstyle. Her skill should generally be used before your DPS characters take action so that your DPS can be buffed. With Ruan Mei's technique, 2pc Vonwacq, or enough SPD, this can easily be achieved. Her technique also saves one skill point at the start of battle, allowing even easier access.

Ideally, you want to cast Ruan Mei's ultimate every three turns (this will be referred to as 3T ult). This is so you can have as much ultimate uptime as possible. Ruan Mei's value mostly comes from her ultimate, so higher uptime means more buffs. The problem is that this is pretty difficult to achieve. Her signature light cone does not provide enough energy to achieve a 3T ult, and Energy Recharge buffs and stats are extremely rare.

Example of a 3T ultimate with S4 MotP by sealary.

Is 3T ult really necessary, though? Not really, but it is ideal. It is more important to reach the minimum recommended Break Effect (180%) before focusing on a 3T ult. If you're comfortable with casting Ruan Mei's ultimate every four turns instead, then that's fine! While you may lose out on some buffs, Ruan Mei certainly isn't "unplayable" with a 4T ult. Again, it is more important to focus on having at least 180% Break Effect.

Still, it is best to try to optimize your ultimate uptime as much as possible. Even if you can't achieve a 3T ult, you should still try to make the most of your energy and ult as much as you can with what you have. It is best to aim for 4T ult as a minimum goal and 3T as the ideal.

If you are unsure if you are able to achieve a 3T or 4T ultimate with what you have, you can check our Energy Requirements section in this guide!

Example of a 4T ultimate with S2 Dance! Dance! Dance! by sealary.

Traces

Ruan Mei's traces are mainly focused on buffing her allies, specifically around break mechanics. She relies on a high amount of break effect, and she buffs Break Effect and Weakness Break Efficiency for her allies.

Trace Priority

tracepriority

Ruan Mei's value comes from her ultimate and her skill. As a Harmony character, she focuses on buffing her allies rather than dealing high amounts of damage. Her ultimate and skill boost her allies' damage, her ultimate increases the RES PEN(1) of her allies, and her skill increases the overall damage and Weakness Break Efficiency of her allies. This causes these two traces to be her most valued traces and the ones that should receive the most priority.

  1. RES PEN is short for resistance penetration. What is RES PEN and how does it work? Check out the Trace Overview below and read more about it in her Ultimate description!

Ruan Mei's ascension traces are also quite decent. Her second and fourth ascension traces are very useful in improving her support capabilities, and they should definitely be activated.

Trace Overview

Basic ATK: Threading Fragrance

Deals a minor amount of Ruan Mei’s ATK as ICE DMG to a single enemy. Generates 20 Energy for Ruan Mei.

basic

This trace should be the least prioritized, as it deals very minimal damage. Furthermore, Ruan Mei relies on break effect stats rather than CRIT stats, so this trace will not be very useful.

Skill: String Sings Slow Swirls

Ruan Mei gains Overtone, lasting for 3 turns and decreases in 1 usage at the start of her turn. While Overtone is active, all allies’ DMG increases and Weakness Break Efficiency increases by 50%. Generates 30 Energy for Ruan Mei.

skill

This is one of Ruan Mei's most valuable traces. However, as mentioned above, Ruan Mei is SP positive, meaning that she will use a Skill > Basic > Basic playstyle. In turn, this means that her skill does not need to be prioritized over her ultimate, which is her most important trace. Furthermore, as Ruan Mei's passives already buff her allies' DMG, leveling up her skill will lead to diminishing returns. Despite this, you'll still want to level this trace as much as possible eventually. First prioritize her ultimate, and then prioritize this trace.

Ultimate: Petals to Stream, Repose in Dream

Ruan Mei deploys a field that lasts for 2 turns. The field's duration decreases by 1 at the start of her turn.

While inside the field, all allies' All-Type RES PEN increases and their attacks apply Thanatoplum Rebloom to the enemies hit.

When these enemies attempt to recover from Weakness Break, Thanatoplum Rebloom is triggered, extending the duration of their Weakness Break, delaying their action by an amount equal to a portion of Ruan Mei's Break Effect plus 10%, and dealing Break DMG equal to a portion of Ruan Mei's Ice Break DMG.

Enemy targets cannot have Thanatoplum Rebloom re-applied to them until they recover from Weakness Break.

ult

It is highly recommended to level Ruan Mei's ultimate. This is her bread and butter, and it is what makes her very valuable to your team. The reason why this trace should be highly prioritized is due to the All-Type RES PEN that it provides, making Ruan Mei a universal shredder.

What is RES PEN and how does it work?

RES PEN, short for Resistance Penetration, refers to when the character ignores the enemy's resistance. This is an incredibly useful stat, as enemy resistance affects the damage it takes quite significantly. With RES PEN, your damage output increases greatly, especially against enemies with high resistance.

For example, if an enemy has 0% Ice RES, they will take 100% of the Ice DMG inflicted on them. With 25% RES PEN, the enemy will now take 125% of the Ice DMG received. This means that your damage will increase by 25%.

If an enemy has 60% Ice RES, they will only take 40% of the Ice DMG inflicted on them. Without RES PEN, you will lose out on a lot of damage due to the enemy's resistance. With 25% RES PEN, however, the enemy's Ice RES drops from 60% to 35%. This means that the Ice DMG it receives is now 65% instead of 40%. While this doesn't look all that impressive, the DMG dealt has increased by 62.5%, which is quite a lot!

In conclusion, RES PEN is incredibly valuable. Ruan Mei provides All-Type RES PEN, meaning that she is able to decrease all types of enemy resistance, making her a flexible and strong support.

Talent: Somatotypical Helix

talent Increases SPD for the team (excluding Ruan Mei). When allies Break an enemy target's Weakness, Ruan Mei deals to this enemy target Break DMG equal to a portion of her Ice Break DMG.

This trace is nice to have, giving allies a free SPD boost. However, it does not increase SPD by very much, and it should not be relied on for SPD tuning, so it shouldn't be prioritized over others.

A2: Candle Lights on Still Waters

a2 In battle, for every 10% of Ruan Mei's Break Effect that exceeds 120%, her Skill additionally increases allies' DMG by 6%, up to a maximum of 36%.

This trace should definitely be prioritized. When Ruan Mei's Break Effect reaches 180% or higher, her allies will recieve a free 36% DMG increase from her skill. This is also why having at least 180% Break Effect is recommended.

A4: Days Wane, Thoughts Wax

a4 Ruan Mei regenerates 5 Energy at the start of her turn.

This trace should be prioritized. Because Ruan Mei's ultimate is important, she needs as much energy as she can get. This trace also makes 3T ult possible and helps with Ruan Mei's energy management.

A6: Inert Respiration

a6 Increases Break Effect by 20% for all allies.

This trace is decent, but it's not as valuable as the other ascension stats. Still, it is recommended to prioritize this trace. It helps make reaching the recommended 180% Break Effect threshold easier, allowing you to invest in other stats, and it benefits any allies who need Break Effect. NOTE: THIS TRACE DOES NOT TAKE EFFECT UNTIL YOU ARE IN BATTLE.

Eidolons

Most players won't be pulling for eidolons, but in case you are someone who wants to know which eidolon is the best, we have you covered. If you manage to get lucky or have some extra funds, it is recommended to pull for Ruan Mei's E1. Her first eidolon is extremely powerful and offers a free DEF shred. Between E1 and signature LC, definitely pull for Ruan Mei's E1.

Eidolon Comparisons

Comparison graph will be added soon...

Eidolon Overview

e1

While the Ultimate's field is deployed, the DMG dealt by all allies ignores 20% of the target's DEF.

  • Ruan Mei's best eidolon
  • Between E1 and LC, prioritize E1
  • Offers unconditional DEF shred (think 4PC Genius set)

e2

With Ruan Mei on the field, all allies increase their ATK by 40% when dealing damage to enemies with Weakness Break.

  • Mediocre eidolon
  • Generic team-wide DMG increase
  • Allows for allies to use SPD boots

e3

Ultimate Lv. +2, up to a maximum of Lv. 15. Talent Lv. +2, up to a maximum of Lv. 15.

  • Generally good eidolon
  • Levels up talent and ultimate, which is quite valuable
  • Not necessary for Ruan Mei

e4

When an enemy target's Weakness is Broken, Ruan Mei's Break Effect increases by 100% for 3 turn(s).

  • Mediocre eidolon
  • Allows for stat redistribution
  • General increase in personal DMG

e5

Skill Lv. +2, up to a maximum of Lv. 15. Basic ATK Lv. +1, up to a maximum of Lv. 10.

  • Underwhelming eidolon
  • Ruan Mei's Basic ATK should be least prioritized
  • Only get E5 if you plan to get E6

e6

Extends the duration of the Ultimate's field by 1 turn(s). The Talent's Break DMG multiplier additionally increases by 200%.

  • Ruan Mei's second best eidolon
  • Higher ultimate uptime, which is very valuable
  • Significant increase in Ruan Mei's personal DMG

Light Cones

Ruan Mei's light cone situation is quite interesting. Her signature light cone, while it is quite good due to the raw stats it offers, does not provide enough energy to achieve 3T ult. This makes other budget-friendly options a viable choice for Ruan Mei, and some can even compare to or outperform Ruan Mei's signature light cone. We won't deny that Ruan Mei's light cone is extremely beautiful, though. If you are unsure of which light cone works best for your energy needs, check out our Energy Requirements section.

Light Cone Mathematical Comparisons Notes
sig TBD% Past Self in Mirror is Ruan Mei's signature and best in slot light cone. While it doesn't provide a lot of energy to ensure a 3T ultimate, you only need to be hit once or twice to achieve a 3T ult. The other benefits it provides, including high SP positivity, are quite powerful as well, allowing it to slightly edge out S5 MotP. It greatly reduces the need for Break Effect, allowing you to invest in other stats.
motps5 TBD% Memories of the Past is Ruan Mei's best 4-star light cone and a great budget alternative to PSiM. It provides Ruan Mei's most needed stats, Break Effect and energy. At S3+, Ruan Mei only needs to be hit once to ensure a 3T ultimate. At S5, it competes with PSiM because it guarantees a 3T ultimate.
cogs TBD% Meshing Cogs, a popular budget light cone choice for Harmony characters due to the energy it provides, is a very viable option for Ruan Mei. Because it is a 3-star light cone, it is easily accessible for F2P players. At S5, this light cone outperforms S2 Memories of the Past due to the energy it provides. However, because it does not provide Break Effect, it performs worse than PSiM and S5 MotP.
sparklelc TBD% Earthly Escapade is Sparkle's signature light cone. While it doesn't provide any energy, which also means its crit buff passive only has about 50% uptime, the buffs it provides still prove useful. However, it is a much more viable option for Sparkle, as it is tailor-made for her.
dance TBD% Dance! Dance! Dance! is a possible option due to its basic utility, which advances forward all allies upon casting the wearer's ultimate. However, because it does not provide any of Ruan Mei's needed stats, it is not recommended over the above options.
planetary TBD% Planetary Rendezvous is an option for Ruan Mei if you are using her in Ice teams. However, Ruan Mei already provides DMG buffs for her allies, and having more leads to diminishing returns. Furthermore, this light cone does not provide Break Effect or Energy, Ruan Mei's most needed stats.
bronya TBD% But the Battle Isn't Over, Bronya's signature light cone, is generally NOT recommended unless at high superimpositions. The only part of it that benefits Ruan Mei is the energy it provides, but it is not enough to justify using it over the above options.

Relic Sets

Ruan Mei mainly needs Break Effect, SPD, and Energy Regeneration Rate, as those are the stats that help improve her support capabilities the most. Because she is a support character and Break DMG cannot crit, offensive stats such as CRIT and ATK don't contribute anything to her playstyle. Do not invest in those.

When choosing a relic set for Ruan Mei, prioritize reaching 180% Break Effect (160% without Ruan Mei's Inert Respiration trace) first. If you are lacking Break Effect, it may be better to run a relic set that provides more Break Effect, depending on what you need. If you are able to cast Ruan Mei's ultimate often and reach the required amount of Break Effect without a Break Effect relic set, then 4PC Hackerspace is recommended. Otherwise, consider using a 2PC 2PC alternative or even a different set.

For 2PC 2PC combinations, it is recommended to run a 2PC Break Effect set with 2PC Hackerspace. When choosing to farm between Watchmaker and Thief, choose the set that is more fuel-efficient. If you need the Pioneer set, farm for Watchmaker. If you need the Boxing set, farm for Thief.

4PC Relic Recommendations

messenger

Increases SPD by 6%. When the wearer uses their Ultimate on an ally, SPD for all allies increases by 12% for 1 turn.

  • Increases personal SPD
  • Increases SPD for all allies
  • Only recommended if you have enough Break Effect and ultimate uptime

2pc

Increases the wearer's Break Effect by 16%. Increases SPD by 6%.

  • Increases Break Effect
  • Increases SPD
  • Recommended if you need a balance of additional SPD and Break Effect

thief

Increases the wearer's Break Effect by 32%. When the wearer inflicts Weakness Break on an enemy, regenerates 3 Energy.

  • Greatly increases Break Effect
  • Regenerates energy for Ruan Mei if she breaks the enemy
  • Recommended if you are lacking Break Effect and/or ultimate uptime

watchmaker

Increases the wearer's Break Effect by 16%. Increases Break Effect of all allies (including the wearer) by 30% for 2 turns upon using Ultimate.

  • Greatly increases Break Effect
  • Increases Break Effect for all allies
  • Only recommended if you are using a break-focused DPS

2PC Planar Ornament Recommendations

vonwacq

Increases the wearer's Energy Regeneration Rate by 5%. When the wearer's SPD reaches 120 or higher, the wearer's action is Advanced Forward by 40% immediately upon entering battle.

  • Increases Energy Regeneration Rate
  • Allows for higher ultimate uptime
  • Advances forward at the start of battle
  • If Ruan Mei's technique is used, saves 1 skill point

penacony

Increases wearer's Energy Regeneration Rate by 5%. Increases DMG by 10% for all other allies that are of the same Type as the wearer.

  • Increases Energy Regeneration Rate
  • Allows for higher ultimate uptime
  • Increases DMG% for matching-type teammates
  • Recommended if running with an Ice DPS

talia

Increases the wearer's Break Effect by 16%. When the wearer's SPD reaches 145 or higher, the wearer's Break Effect increases by an extra 20%.

  • Increases Break Effect
  • Does not provide energy, so ultimate uptime will be lower

keel

Increases the wearer's Effect RES by 10%. When the wearer's Effect RES is at 30% or higher, all allies' CRIT DMG increases by 10%.

  • Increases allies' CRIT DMG
  • Ruan Mei does not really need Effect RES compared to other stats

Relic Stats

stats

As mentioned before, Ruan Mei is a support character who is focused on buffing her allies. She is not meant to deal high amounts of damage. This means that it is better to focus on stats that will improve Ruan Mei's support capabilities. Defensive stats as well as supportive stats like SPD are appreciated, and as Ruan Mei scales off Break Effect, you will obviously need some Break Effect on your relics. It is very important to reach the recommended 180% (160% without Ruan Mei's Inert Respiration trace) Break Effect.

For Ruan Mei's chest piece and planar sphere, choose whichever relic has better substats. HP and DEF are both equally needed for Ruan Mei. For her link rope, it is better to use an ERR rope, as Ruan Mei requires a lot of energy to optimize her ultimate uptime. However, if you are lacking Break Effect, or if you don't have an ERR rope, using a BE rope is fine. Using an ERR rope eventually is crucial, however.

Stat Priority

statpriority

Break Effect should be the most prioritized relic substat, as most of Ruan Mei's kit revolves around Break Effect. Ruan Mei needs at least 180% Break Effect in total in order to maximize her passive. Ruan Mei's Inert Respiration trace does not take effect until you are in battle, so technically, you only need 160% Break Effect. However, for the sake of consistency, the minimum will be referred as 180%. More Break Effect is generally always better as long as you're not sacrificing other stats.

SPD should also be prioritized, as it allows Ruan Mei to have more turns per cycle, keeping her buffs and ultimate uptime higher. At least 143 SPD is recommended. Ruan Mei has a total of 134 SPD from her traces and SPD boots, so 143 SPD can be obtainable with a few substat rolls and/or 2PC Messenger Traversing Hackerspace. Like Break Effect, more SPD is better as long as you are not sacrificing other stats.

Defensive stats such as Effect RES, HP, and DEF are also helpful for Ruan Mei. In combat, she wants to get hit a couple times in order to gain energy, meaning survivability is important to her. With some defensive stats, Ruan Mei's survivability will naturally increase. However, keep in mind that Break Effect and SPD should be prioritized over these stats.

Energy Requirements

Ruan Mei requires as much energy as she can, as her ultimate is extremely valuable for her team. As mentioned before, it is ideal to cast a 3T ultimate for as much uptime as possible. However, 3T ultimate is difficult to achieve, so a 4T ultimate is fine as well if you are lacking in Break Effect. Below are some energy and light cone combinations to determine if you can achieve a 3T or 4T ultimate with Ruan Mei.

A special case is if you have Huohuo on your team. Huohuo will lower your rotation by one turn.

Note that to achieve 124.4% ER, you must use an ERR rope and Penacony/Vonwacq. To achieve 119.4% ER, you must use an ERR rope. To achieve 105% ER, you must use Penacony/Vonwacq.

Total Energy Light Cone Turns to Cast Ultimate Notes
124.4% S1 PSiM 4 With this build, you may need to be hit once or twice to achieve 3T ult. This build is highly recommended because it allows you to focus on Energy Regeneration, and it is the most SP positive among the ones listed here.
119.4% S1 PSiM 4 With this build, you may need to be hit once or twice to achieve 3T ult. It is not recommended to use this build unless you cannot reach 180% Break Effect.
124.4% S5 MotP 3 This build is highly recommended, as you can comfortably 3T ult with this build without losing out on the necessary Break Effect.
119.4% S5 MotP 4 With this build, you may need to be hit once or twice to achieve 3T ult.
124.4% S3 MotP 4 With this build, you will only need to be hit once to achieve 3T ult.
119.4% S3 MotP 4 With this build, you may need to be hit once or twice to achieve 3T ult.
124.4% S5 Meshing Cogs 3 While this build achieves 3T ult, you may be lacking in Break Effect. If you have less than 170% Break Effect with this build, use Talia/BE rope instead.
119.4% S5 Meshing Cogs 4 If you are lacking in Break Effect, it is recommended to use this build. You will be able to have more Break Effect, and you will only need to be hit once to achieve 3T ult.
100% S5 Meshing Cogs 4 You can use this build if you are severely lacking in Break Effect. However, if you are able to reach the minimum 180% Break Effect without Talia/BE rope, use Penacony/Vonwacq/ERR rope instead.
124.4% Other 4 This build will comfortably put you at 4T ult, but you may be lacking in Break Effect.
119.4% Other 4 This build will comfortably put you at 4T ult, and with 2PC Talia, it will help you reach the necessary Break Effect.
105% Other 4-5 This rotation is inconsistent and is generally not recommended.

Teammates

Due to her universal buffs, such as SPD increase, DMG% increase, and All-Type RES PEN decrease on enemies, Ruan Mei can fit in most teams and can effectively support most DPS characters. If you're wondering if Ruan Mei can work well with your main DPS, the answer is yes if they're not Clara. Even characters who don't benefit as much from Break Effect still benefit form Ruan Mei due to her strong buffs. Below are some characters who work particularly well with Ruan Mei.

Notable Synergies

Character Notes
asta Asta is a great budget option to use with Ruan Mei. She naturally has incredibly toughness damage, so she can break very often, which goes well with Ruan Mei's kit. Fire characters also have a high break multiplier, so a higher break effect allows for more break damage. Furthermore, both Asta and Ruan Mei buff speed, so you will be able to have several turns before the enemy does. Another great thing about Asta is that she buffs ATK% while Ruan Mei buffs DMG%, which allows for less diminishing returns.
sw Silver Wolf is a teammate who will pair well with Ruan Mei. Her main gimmick revolves around weakness implant, and Ruan Mei is focused around teams who will break the enemy. Silver Wolf guarantees that your team will be able to break the enemy and use Ruan Mei to her full potential. Also, Silver Wolf's DEF shred is valuable, and she deals a decent amount of toughness break damage herself. She especially shines with Ruan Mei when using a break effect-focused build.
xueyi Xueyi gains a DMG boost based on her Break Effect, a stat that Ruan Mei increases for her allies. Furthermore, Xueyi's ultimate deals Toughness DMG regardless of their weakness element, which allows for easier breaking of the enemy. Xueyi is also a 4-star character, making her more accessible for F2P players.
sushang Sushang benefits from Break Effect, and she benefits greatly from enemies being weakness broken, making her a great option to go with Ruan Mei. Additionally, Sushang has high Weakness Break Efficiency, which allows her to break often. Physical characters also have a high break multiplier, so a higher break effect allows for more break damage. Furthermore, Sushang is a 4-star character, which means she is more accessible for F2P players.
kafka Kafka works extremely well with Ruan Mei. This is because Ruan Mei's buffs, such as RES PEN and DMG%, affect DoT, and DoT still occurs while enemies are weakness broken. Furthermore, breaking enemies also triggers DoT, and Ruan Mei allows her allies to break more often.
welt Welt deals 20% more DMG to enemies inflicted with Weakness Break, making him a great option to pair with Ruan Mei. He also slows enemies, which is a great utility to have and one that synergizes quite well with Ruan Mei. Ruan Mei's Weakness Break and SPD buffs paired with Welt's Slow debuffs make a great team.
misha Misha is a new 4-star Ice DPS character for patch 2.0. He benefits from the Penacony, Land of Dreams relic set on Ruan Mei as an Ice DMG dealer. Furthermore, due to his rarity, he is considered a budget option who is more accessible for F2P players. While he doesn't exactly benefit from Ruan Mei's Break Effect buffs, his ultimate, which can freeze enemies, can help further delay enemy actions.

Notable Anti-Synergies

Below are some characters who don't synergize as well with Ruan Mei. However, these characters (except Clara) can still be used with Ruan Mei, and Ruan Mei can still be a top teammate pick for them. They will just need a little more consideration when being used with Ruan Mei. The only character who truly does not work with Ruan Mei is Clara.

Character Notes
clara Clara is one character who absolutely won't work with Ruan Mei. Clara relies on getting hit in order to counter enemies, but Ruan Mei helps keep enemies weakness broken. If enemies are broken, then Clara can't get hit.
himeko Himeko isn't the most anti-synergistic with Ruan Mei due to the fact that she wants to break as many enemies as possible. However, Ruan Mei also extends Weakness Break (her "second break" from her Thanatoplum Rebloom does not add any stacks for Himeko), which means that it will take longer for Himeko to gain stacks and trigger her follow-up attack. She can still be used with Ruan Mei because she benefits from Weakness Break buffs, but she will have a harder time gaining stacks.
seele Seele is also in a similar boat as Himeko. She isn't the most anti-synergistic with Ruan Mei, and she greatly benefits from her buffs, making Ruan Mei a top pick for Seele. However, Ruan Mei's Thanatoplum Rebloom from her ultimate can accidentally "steal" Seele's kills, preventing Seele from triggering her Resurgence passive. This can be worked around, but it needs to be considered when using Ruan Mei and Seele together.

Team Composition Examples

Below are some example team compositions for Ruan Mei. These are not the only team compositions that can be used with Ruan Mei; as mentioned before, she is an incredibly flexible unit. Rather, these teams are some notable examples to provide a general idea of how to use Ruan Mei in various team compositions.

Kafka DoT

dot

Topaz Follow-Up

fua

Dual Carry

dual

Hypercarry

hyper

Character Comparisons

Ruan Mei may be the first limited 5-star Harmony character, but she isn't the only Harmony or support character in the game. There are many other great characters to use, and many may wonder how she may compare to those characters.

Character Notes
bronya Bronya is currently the only other 5-star Harmony character, and as a Harmony character, she is focused on buffing her allies' DMG. However, that is where their similarities end. Bronya is focused on single-target buffs, while Ruan Mei buffs the entire team at once. Furthermore, Bronya's kit revolves around increasing ATK% and CRIT DMG, whereas Ruan Mei's kit focuses on increasing Weakness Break Efficiency, Break Effect, and SPD. Because they are so different, it is better to consider what you need and which DPS character you are using. As a standard character, however, Bronya is easier to obtain than Ruan Mei.
tingyun Tingyun is generally regarded as one of the best characters in the game due to how versatile and universal she is as a support. It's even better that she's a 4* character, making her very accessible for F2P players. Tingyun's ultimate, which restores energy for allies, is also something extremely useful. However, again, as Ruan Mei and Tingyun do different things, you should use whoever benefits your team more. You can even use both characters together. Tingyun buffs ATK% while Ruan Mei buffs DMG%, which reduces diminishing returns.
asta Asta is a popular Harmony option for many players due to her being completely free to obtain. Despite being a budget-friendly character, Asta provides a lot of value due to her ATK% buffs and her huge flat SPD boost from her ultimate. While Ruan Mei and Asta may seem similar due to the fact that they both provide buffs and increase SPD, they are quite different. Ruan Mei buffs DMG%, while Asta buffs ATK%. This makes Asta someone who runs very well with Ruan Mei, rather than someone to be replaced by Ruan Mei.
pela Pela is a Nihility character, while Ruan Mei is a Harmony character. However, as both are Ice supports, they may be compared quite often, especially for Ice DMG-focused teams. Because Ruan Mei and Pela are both different characters who provide different things, it is again recommended to run them together if possible. However, if you must choose one or the other, choose whoever benefits your DPS more. Ruan Mei buffs Break Effect and Weakness Break Efficiency, which might be more valuable to certain characters.
yukong Yukong is also a free-to-obtain character, making her another popular Harmony choice for players. However, without E6, Yukong's buff window is very small. Ruan Mei's buff window is much longer, making her a very comfortable choice for players. Yukong also buffs ATK% and CRIT while Ruan Mei buffs DMG%, so it is possible to run them together.

Frequently Asked Questions

If you didn't read through this guide thoroughly, you probably don't know the answers to these commonly asked questions, but don't worry. If you just skipped to the end to find the answers to these questions, we've got you covered.

E1 or Signature Light Cone?

Ruan Mei's E1 is highly recommended over her light cone. There are a couple great alternatives to Ruan Mei's signature light cone, and at high superimpositions, they may even outperform Ruan Mei's light cone. This is because Ruan Mei's light cone does not provide enough energy to ensure a 3T ult, and the Break Effect it gives at S1 is comparable to the amount of Break Effect S5 Memories of the Past gives.

Conversely, Ruan Mei's E1 is incredibly valuable. As her best eidolon, it ignores 20% DEF during Ruan Mei's ultimate. This is basically like having 4PC Genius of Brilliant Stars, which is a popular relic set for even non-Quantum DPS characters. That's how good DEF shred is.

ERR or BE rope?

It is recommended to run an ERR rope over a BE rope. Ruan Mei's ultimate is very valuable and provides All-Type RES PEN, a very helpful buff. Energy Regeneration is also not easily obtained, as it cannot be gained via relic substats. The only relic with an Energy Regeneration main stat is the link rope, so that is the only Energy Regeneration you can possibly obtain via relics.

Break Effect, on the other hand, can be obtained via relic substats, Thief of Shooting Meteor, and Ruan Mei's traces. It is not difficult to reach the recommended 180% without a BE rope.

Because Ruan Mei's ultimate is so powerful, it is highly recommended to have as much Energy Regeneration as possible. This is why ERR rope is recommended over BE rope.

Is 3T Ult Really Necessary?

While a 3T ult is optimal, it's not necessary. It is better to focus on achieving the minimum amount of Break Effect (180%) before focusing on achieving a 3T ult. However, even if you cannot achieve a 3T ult, still aim for as high ultimate uptime as possible. Ruan Mei's ultimate is very valuable, so the more you can cast your ultimate, the better.

How much Break Effect can I sacrifice for 3T Ult?

It is recommended to first aim for 180% Break Effect, then to focus on 3T ult. If you have less than 170% Break Effect, it is better to settle for a 4T ult instead, as losing out on the recommended Break Effect negatively affects Ruan Mei more than having less ultimate uptime. However, it is not recommended to settle for anything more than a 4T ult. A 5T ult is not recommended, and using an ERR rope is still recommended over a Break Effect rope. You can see what combination of light cones and ERR works best for you in our Energy Requirements section.

How much Break Effect is too much?

While the recommended minimum Break Effect is 180%, you can definitely have more Break Effect. There is no limit to how much Break Effect to have, but you should not be sacrificing other stats for Break Effect. Once you hit 180% Break Effect, focus on other stats; if you have extra Break Effect to spare even after hitting the recommended stats, that's perfectly fine.

Can I run a Break Effect rope?

In all situations, a Break Effect rope should only be used if you do not have an ERR rope. This goes for when you cannot reach 180% Break Effect as well. Even with other energy sources, having an ERR rope is still recommended. It is generally more beneficial for your team to cast Ruan Mei's ultimate more often, and an ERR rope is the largest source of energy for any character. Sacrificing over 19% energy for more Break Effect, which is a stat that can be obtained via relic substats, is not worth it. The only exception for this is if you are willing to 4T ult with S5 Meshing Cogs.

Closing & Final Thoughts

In conclusion, Ruan Mei is a strong buffer who can fit in any team. She is future-proof and will remain a strong unit even in later patches. She is slightly costly, and she isn't meant to replace other Harmony units, but she shines in her own way. Also, it gives players a chance to invest in a stat that wasn't commonly invested in before.

Huge thanks to our Theorycrafting Team for their work in creating this guide! From working on calculations to answering questions, their contributions have been invaluable.

This guide will be updated as future content updates and changes Ruan Mei's recommended playstyle. Thanks for reading, and we hope you found this guide helpful!