Match the passive to your combat pattern

At R1, Iron Sting rewards Elemental DMG with a stackable damage bonus. Prototype Rancour stacks ATK and DEF from Normal or Charged Attack hits. Prototype Amber restores its wielder’s Energy and heals the party after an Elemental Burst. Compare the trigger you can use and the secondary stat before committing a billet, then confirm formula access.

Genshin Impact identity and recipe snapshot · HoYoWiki: Iron Sting forging formula · HoYoWiki: Prototype Rancour forging formula · HoYoWiki: Prototype Amber forging formula