Diona

4★

CryoBowShielder

TL;DR

Hold Diona's Skill for a shield, press her Burst for a puddle that heals whoever stands in it, then get out of the way. She does both jobs at once, so one slot covers your shielding and your healing. Once her Witch's Revelation quest is done the paws also keep firing on their own for 20 seconds at anything your team reacts on, which is what puts her in Stellar reaction teams.

Rotation

Hold Skill (E) until she dashes back and fires. That's the big shield.
Press Burst (Q) on top of the enemies, since it has to cover your damage dealer too.
Swap out. The puddle heals and chips away for about 12 seconds.
Come back every 20 seconds or so for the next Burst. Re-shield whenever hers has gone.

Abilities

Skill (E)	Fires icy paws that shield whoever is on the field when they connect. Tap for two paws on a 6 second cooldown, hold for five on a 15 second one. The shield scales off her Max HP and it's very good against Cryo specifically. After her Witch's Revelation quest, for 20 seconds after you cast it she also fires three more paws whenever a teammate triggers Superconduct, Stellar-Conduct, Cryo Swirl or Stellar Swirl, at most once every 3.5 seconds. Those paws put Cryo on the enemy but give no shield and no particles.
Burst (Q)	Throws a drink that leaves a mist on the ground for about 12 seconds. It heals anyone inside and ticks slow Cryo damage on any enemy in it. Costs 80 Energy, 20 second cooldown. Enemies caught in it also lose 10% Attack.

Skill (E)

Fires icy paws that shield whoever is on the field when they connect. Tap for two paws on a 6 second cooldown, hold for five on a 15 second one. The shield scales off her Max HP and it's very good against Cryo specifically. After her Witch's Revelation quest, for 20 seconds after you cast it she also fires three more paws whenever a teammate triggers Superconduct, Stellar-Conduct, Cryo Swirl or Stellar Swirl, at most once every 3.5 seconds. Those paws put Cryo on the enemy but give no shield and no particles.

Burst (Q)

Throws a drink that leaves a mist on the ground for about 12 seconds. It heals anyone inside and ticks slow Cryo damage on any enemy in it. Costs 80 Energy, 20 second cooldown. Enemies caught in it also lose 10% Attack.

The one mechanic to understand

Hold the Skill, don't tap it.

Each paw that lands adds about 2.4 seconds to the shield. The held version fires five instead of two while also making the shield roughly 75% stronger. So holding gets you something like a 12 second shield and tapping gets you 5 seconds of a much weaker one. The hold has a longer cooldown, 15 seconds against 6, but the shield lasts long enough that you don't need it back sooner. Tap only when you want the cooldown back fast for energy particles, or when there is nothing to shield against and you just want Cryo on the enemy.

The shield also puts Cryo on your own character for a moment as it forms. That's usually fine or even useful. It will react with a carry who applies their own element though, so if your Pyro character's numbers drop right after a shield, that is why.

What actually matters

Max HP is both of her jobs. The shield scales off it and so does the healing. HP% on everything. Attack does nothing for her.
Energy Recharge and a fair bit of it. 80 Energy on a 20 second cooldown is a real cost for a character who only presses two buttons. Somewhere around 160% keeps the Burst coming every rotation. A Sacrificial or Favonius bow does a lot of that work for you.
Put the puddle where the fight is. It doesn't move and a healing puddle nobody is standing in is just a bit of Cryo damage.
Do the Witch's Revelation quest if she's in a Stellar reaction team. It opens at level 70. The extra paws it adds keep Cryo on the enemy after she has swapped out, so the reactions keep coming without her.

Gear

Weapon	Energy Recharge. Favonius Warbow if you have it, since the extra particles help her afford that 80 cost. Sacrificial Bow is the other easy one and it sometimes hands her Skill straight back.
Artifacts	4-piece Noblesse Oblige for the party Attack bonus. In a Stellar-Conduct or Stellar Swirl team take 4-piece Tenacity of the Millelith instead, since the extra paws from her quest count as Skill hits and keep its 20% Attack buff refreshed while she's off the field.

Sands	Goblet	Circlet	Substats
ER / HP	HP	HP / Healing Bonus	HP / ER

Skip Crit entirely unless you're running Favonius and need the Crit Rate to trigger it.

Works well with

A shield and a heal fit anywhere. These are just what her Cryo does something with. Electro or Anemo give the reactions that set off her extra paws. Hydro freezes. A second Cryo character turns on the resonance bonus against frozen enemies.

Don't bother

Shooting things with her. Her bow damage is nothing and she has no reason to hold the field.
Building Attack or Crit. Neither one touches the shield or the healing.
Aiming carefully with the hold. She dashes backwards as part of it, so aim roughly at the enemy and let the paws find them.

Want the full deep dive? Read Diona on KeqingMains.

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