When she isn’t serving drinks at the Cat’s Tail tavern in Mondstadt, Diona moonlights are one of the strongest support characters in the game. Combining crowd control from her Cryo damage with strong healing potential.
Her Elemental Skill is called Icy Paws, which fires off projectiles that do Cryo damage, with each impact forming a shield on the player character. The shield’s strength scales with her maximum HP. You can press the R2 button to fire two projectiles or hold it for a short time to do a backward dash and fire five projectiles.
Her Elemental Burst ability, Signature Mix, will drop an ice cold beer on the ground, freezing enemies with area of effect damage while healing friendly units over time.
The four-star Sacrificial Bow is an excellent option for Diona, giving a chance for any Elemental Skill to cancel its own cooldown every 30 to 14 seconds. This allows for the main thing you want from any crowd control mage, which is ability spam. You can also use the Favonious Warbow, another four-star bow obtained from Wishes, that will generate energy orbs with critical hits.
For her Artifacts, we would suggest the Maiden Beloved set to take advantage of her healing. This will increase healing effectiveness by 15%, and at four pieces will increase healing received by all party members by 20% when you use an Elemental Skill or Burst. You can get the Maiden Beloved set from the Valley of Remembrance Domain near Dawn Winery in Mondstadt.