Diona Build and Guide

Diona is a 4-star Cryo Bow character commonly played as a sustain on Stellar-Glimmer teams. Her kit packs shielding on Skill and healing on Burst, with the latter providing good Elemental Mastery and Reaction DMG% buffs at C6.

Stellar-Conduct is a reaction that replaces Superconduct when certain characters are on the team. It deals no damage when triggered, instead spawning a Starlight Prism which generates a Polestar Field around it. This applies the 40% Physical RES Shred from the base reaction while also activating Radiance: Stellar-Conduct effects in kit. It additionally provides a DMG Bonus for the Electro and Cryo DMG and a Base Reaction Coefficient for direct Stellar-Conduct damage based on a tally which counts whenever these elements are applied; this starts at 29% and 1.45 at one stack, and increase by 1% and 0.05 to a maximum of 40% and 2 respectively. These bonuses are granted every 4 seconds, with the tally beginning anew each time.

Stellar Swirl meanwhile replaces Cryo Swirl, and activates Radiance: Stellar Swirl effects when triggered. It also deals Anemo Stellar Swirl reaction damage to the target and creates a “Level 1” Vortex; this Vortex levels up after Stellar Swirl is triggered two additional times, exploding after 3 seconds or 5 additional Stellar Swirl triggers to deal Cryo Stellar Swirl reaction damage based on the Vortex’s level. A large jump can be performed just after the Vortex explodes, though this is generally impractical to use. Note that if both Stellar-Conduct and Stellar-Swirl are triggered by the team, Radiance: Stellar-Conduct will take priority.

Similar to other damaging reactions, Stellar damage scales with EM, reaction damage bonuses, ignores DEF, and does not benefit from standard DMG% - unlike typical reactions, it can also CRIT. Stellar Swirl damage from reactions also takes into account the level and stats of all characters who contributed to triggering reaction based on their damage dealt to the enemy: 60% of the stats of the strongest participant, 30% of the second, and 5% for the third and fourth. Direct Stellar damage is considered to be of the element of the unit dealing it and is based on the multiplier and the scaling stat listed in the ability instead of level, with Stellar-Conduct damage additionally being multiplied by the Base Reaction Coefficient. 

Diona’s kit is remarkably simple, though her Elemental Skill has the most mechanics associated with it. The Skill can be Tapped or Held, launching 2 or 5 Icy Paws respectively on cast that deal Cryo damage and create a shield based on her Max HP. The number of Icy Paws fired directly control the shield duration; her Tap Skill lasts for 4.8 seconds with a 6 second cooldown, while her Hold variant lasts for 12 seconds with a 15 second cooldown and is additionally bolstered with a 75% DMG absorption bonus. Each Icy Paw has an 80% chance to generate an energy particle, making her Hold Skill far more efficient in almost all cases and rendering her Tap Skill rarely used.

Diona also has two passives tied to this Skill: Her first Ascension Passive allows her shield to grant a 10% Movement SPD increase and Stamina Consumption reduction, while her Revelation Passive allows her to fire 3 additional Icy Paws at the enemy every 3.5 seconds when Cryo Swirls, Superconduct, or their Stellar variants are triggered for 20 seconds after using her Skill. These Icy Paws don’t actually affect her shield duration or give additional particle generation, but instead serve as a handy way for Diona to get extra Cryo application. 

Her Burst creates a field which heals allies based on her HP and deals negligible Cryo DMG to enemies every two seconds; thanks to her second Ascension Passive, it can also apply a 10% ATK debuff to enemies. The ability has a 12 second duration and a lengthy 20 second cooldown, meaning it can be slightly awkward to play around.

Its real value, however, comes at C6 – granting a 30% Incoming Healing Bonus buff for characters below 50% HP and a 200 Elemental Mastery buff otherwise; if Diona has Radiance: Stellar-Conduct or Radiance: Stellar Swirl, characters in the field additionally are granted a 40% DMG Bonus buff for the corresponding reaction damage. Besides this, it also provides a handy 25% Max HP boost for Diona, increasing her shield strength and healing. This accounts for almost all of her buff profile, and is the reason Diona can be considered in these teams.

Luckily, as a 4* character that has been around since nearly the start of the game, Diona’s Constellations are relatively accessible — though the ones outside of the aforementioned C6 are relatively unremarkable. C1 and C2 both offer good Quality of Life to Diona’s sustain, with the former giving her Burst a 15 Energy refund while the latter increases her shield’s DMG Absorption by 15%. It also provides DMG Bonus to her Icy Paws, which is meaningless since her damage output is fairly lackluster; by a similar principle, the reduced Charged Attack time for Diona while in her Burst radius is also poor since they are almost never used due to her low damage. 

This last point also holds true for her regular Normal and Charged Attacks, especially since her Hold Skill effortlessly procs most relevant weapon buffs such as Favonius Warbow with its 5 hits.