Guide
How the kit works
Bring Qiuyuan in with Attack the Must-Defend when available. It gives him 400 Swordster's Soliloquy and lets you continue with the third stage of his special Basic Attack. Each stage of that attack grants another 100 points, so continue attacking to reach the 600-point cap.
At full points, Verdant Edge enters Inksplash of Mind for up to 8 seconds. Hold Normal Attack to spend the gauge on the three Heavy Attacks in order. Their damage counts as Heavy Attack DMG, while performing them also counts as performing Echo Skill. Quietude Within makes them deal 50% more damage and gives 30 Concerto Energy when the final hit lands. It lasts 10 seconds, can trigger once every 22 seconds and ends early if Qiuyuan leaves the field.
Use Through the Groves for Aero DMG counted as Echo Skill DMG. If you cast the pressed version as an enemy attacks, Qiuyuan ignores that instance of damage and stagnates nearby enemies. Holding it uses STA for a dash; away from targets, the dash continues through the air until you release the skill or run out of STA.
Cast Sundering Strike for Aero DMG counted as Echo Skill DMG and the team Crit. DMG buff. Then use Strike Before Ready to give the incoming Resonator 50% Echo Skill DMG Amplification for 14 seconds or until they switch out.
Build and why
Use the recommended 3-piece Law of Harmony. Its set effects are not specified in the game data, so use it as the listed option without assuming an extra effect.
Emerald Sentence is the first weapon choice. It gives 12% ATK, and casting Echo Skill within 10 seconds of Intro Skill or Basic Attack can grant a stack of 30% Heavy Attack DMG Bonus. Stacks last 12 seconds, with up to two. Echoes of the same name can trigger the effect only once, and the trigger has a 10-second interval.
Emerald of Genesis comes next, with 12.8% Energy Regen and an ATK increase after Resonance Skill. Red Spring is another option, though its Basic Attack DMG Bonus does not apply to the Heavy Attack DMG dealt by Qiuyuan's special Basic Attack. For a 4-star choice, consider Lumingloss: its Resonance Skill effect grants 20% Heavy Attack DMG Bonus for 10 seconds.
As a stat suggestion, look for Crit. Rate. Sundering Strike grants 2% team Crit. DMG for each 1% of Qiuyuan's Crit. Rate above 50%, up to 30%. ATK and Energy Regen are also worth considering for damage and access to Resonance Liberation.
Leveling priority
As a suggested order, level Verdant Edge first, followed by Sundering Strike, Through the Groves, Inkwash and Attack the Must-Defend. This puts the gauge-spending attacks and Liberation ahead of the other parts of his rotation. The available data does not show the values at each skill level, so it does not establish which buffs grow with levels.
For maximum character ascension, you need 170,000 Shell Credit, 4 LF Whisperin Core, 12 MF Whisperin Core, 12 HF Whisperin Core, 4 FF Whisperin Core, 46 Truth in Lies and 60 Wintry Bell.
For all skills to maximum, the listed cost is 2,030,000 Shell Credit, 25 LF Whisperin Core, 28 MF Whisperin Core, 40 HF Whisperin Core, 57 FF Whisperin Core, 26 Curse of the Abyss, 25 Inert Metallic Drip, 28 Reactive Metallic Drip, 55 Polarized Metallic Drip and 67 Heterized Metallic Drip. These costs are separate from character ascension.
Resonance Chain nodes worth it
For Resonance Chain upgrades, a useful first consideration is Sword Sheathed, Mind Unclouded (sequence 1). It gives Qiuyuan 20% Crit. Rate and prevents his three gauge-spending Heavy Attacks from being interrupted. The Crit. Rate also helps him reach the cap on his Liberation's team buff.
O Blade, I, Who Teach No More (sequence 2) adds 30% Echo Skill DMG Amplification to Bamboo's Shade for nearby teammates. It is a good option if you want more team support.
O Blade, I, Who Save No More (sequence 3) changes the rotation when Concerto Energy is full outside Inksplash of Mind. Its replacement skill consumes 60 Concerto Energy, restores 400 Swordster's Soliloquy and changes the next sequence of attacks. It also prevents Quietude Within from triggering on the next entry into the state, so read its effects before using it.
You can leave sequences 4 and 5 for later if you prefer the earlier support and rotation changes. Sequence 6 adds damage and a Stagnation effect, but it is optional for the basic rotation.
Teams
Put Qiuyuan before a damage dealer who can take advantage of Echo Skill DMG Amplification, and keep that character on the field to use the 14-second Outro window. Switching them out ends the buff early. Bamboo's Shade gives nearby active teammates a separate Echo Skill DMG Bonus.
Qiuyuan's buffs do not specify a required teammate element. The important part is what damage the incoming character deals, rather than matching Qiuyuan's Aero element.
Common mistakes
Do not switch Qiuyuan out as soon as the gauge fills. Spend it during Inksplash of Mind and land the final hit while Quietude Within is active if you want its 30 Concerto Energy. The gauge cannot refill in that state and is cleared when the state ends.
Do not treat every named Basic Attack as Basic Attack DMG. The special four-stage attack is counted as Heavy Attack DMG, while the gauge-spending Heavy Attacks count as performing Echo Skill. Their listed damage is still Heavy Attack DMG.
Watch the timing on defensive moves. Moments after a Basic Attack or Heavy Attack, Qiuyuan can ignore the next damage instance and counter, but that protection is not described as permanent. Switching away also removes the Stagnation from Through the Groves.
