Qiqi

TL;DR

Rotation

1. Skill (E). The spirit appears and stays for 15 seconds. With the quest done the cooldown is 15 seconds as well, so it can be out for the whole fight.
2. Normal Attack three or four times if the team needs health. Every hit heals the party.
3. Swap off. The spirit follows whoever is on the field and swipes at anything they hit, so the buff and the trickle of healing carry on without her.
4. Burst (Q) whenever you have the Energy. Inside a Polestar Field it adds a Stellar-Conduct hit of its own and the mark heals your carry on every hit they land.

Abilities

The one mechanic to understand

The spirit doubles as the team buff once her quest is done.

Her Witch's Revelation quest opens at level 70 and gives her an extra passive that changes the character. The Skill cooldown drops from 30 seconds to 15, so the spirit never has to be away. While it's out and the team is standing in a Polestar Field, everyone's Stellar-Conduct damage goes up 50%. In an Anemo team a nearby Stellar Swirl switches the same 50% onto Cryo swirls for 8 seconds instead. The field only comes from a Snezhnaya teammate whose passive turns Superconduct into Stellar-Conduct, so on her own she gets nothing out of it. The 50% is a fixed number: it does not grow with her Attack, her talent levels or anything on her artifacts, which is why her gear is about keeping the Burst fed and carrying a second buff on an artifact set. The healing still works the old way, off her Attack. In full it only arrives while she's on the field swinging.

What actually matters

• Do the Witch's Revelation quest. Get her to level 70 and play it. Without it the Skill cooldown is 30 seconds and there is no buff.
• Somebody has to make the field. Her buff only switches on inside a Polestar Field, which takes an Electro teammate and a Snezhnaya character who upgrades Superconduct.
• Energy Recharge. The Burst costs 80 and the spirit's particles don't cover it on their own, so she needs a lot of it to press the Burst every rotation.
• Attack, for the healing. Everything she heals scales off it. Max HP does nothing, which catches people out.

Gear

Energy Recharge until she can Burst every rotation. As pulled that is around 240% in a Stellar-Conduct team where she is the only other Cryo character, less with a second Cryo teammate. Until you have it, the Skill is the rotation and the Burst is a bonus when it's up. Crit Rate on the circlet is only there for the Favonius passive, so with any other sword take Attack.

Works well with

ElectroAnemo

Electro makes Superconduct, which a Snezhnaya teammate turns into Stellar-Conduct and the field her buff needs. Anemo swirls her Cryo instead. A Stellar Swirl then moves her buff onto those swirls for 8 seconds.

Don't bother

• Maiden Beloved or any other healing set. The healing comes free with her swings in a Stellar-Conduct team. The set slot is worth more as Tenacity's Attack buff.
• Healing Bonus or Max HP main stats. Attack sizes the healing and nothing in her kit reads Max HP.
• Levelling her talents for the buff. The 50% is fixed, so talent levels only grow the healing and her own small Cryo hits.
• Noblesse Oblige unless she really can Burst every rotation. At 80 Energy most builds cannot. An Attack buff that never goes off is no buff.