Rosaria

Rosaria, a sister in Mondstadt's Church of Favonius.
A sister of the church, though you wouldn't know it if it weren't for her attire. An unusual woman with sharp, piercing words and a cold manner.
Her movements are unpredictable. She often leaves without notifying anyone. She acts with some kind of purpose, but others don't seem to know exactly what she stands for...

Source: https://genshin.hoyoverse.com/en/character/mondstadt?char=16