Blade of Atonement is a 4 star Claymore obtained from Weapon Event Wishes in Genshin Impact.
Repentance and Redemption
Triggering an Elemental Reaction increases the equipping character’s Elemental Mastery by 64/80/96/112/128 for 12s, while triggering a Stellar Glimmer reaction increases their ATK by 16%/20%/24%/28%/32% for 12s. The aforementioned effects can trigger even when the character is not on the field.