Increase Energy recharge by 24/30/36/42/48% for 10s after using an Elemental Skill.
In Game Description
A national treasure of Byakuyakoku stored in the Dainichi Mikoshi. With the coming of the Serpent God, this item was used to notarize great oaths and wishes.
How to Get Oathsworn Eye?
Can be obtained from Genshin Impact 2.5 event: Three Realms Gateway Offering event
Weapon Upgrade Materials
Here’s all material required to upgrade Oathsworn Eye catalyst: