Durin's kit is uniquely built around two distinct forms, each serving a different role depending on how you want to play him.

White Form is his dedicated support mode. When activated, it enables consistent off-field Pyro application to enemies, making it excellent for keeping reactions like Overloaded, Burning, or Vaporize going without needing Durin on the field. On top of that, it applies Pyro and Elemental RES Shred to enemies, boosting the team's overall damage output. This makes White Form the go-to choice when you want Durin to carry the team without being in the spotlight.

Dark Form shifts Durin into a personal damage role, allowing him to step up as a Main DPS. In this form, his Elemental Burst hits significantly harder and synergizes especially well with Vaporize and Melt reactions, making him a powerful frontloaded damage dealer. If you're looking to let Durin carry a fight himself rather than support others, Dark Form is the way to go.
Regardless of which form you use, the stat priorities remain the same:

ATK% should be your primary focus, ideally reaching 2000 or above.

CRIT Rate should sit between 60–70% to ensure reliable crits.

CRIT DMG should be pushed to 200% or higher for maximum damage output.

A healthy CRIT ratio of roughly 1:2 (CRIT Rate to CRIT DMG) is the sweet spot, with ATK% being the foundation that amplifies everything else.