faust (blue archive)
The masked (by a paper bag) alter-ego of Hifumi, and (supposed) leader of the Masked Swimsuit Gang. Named in reference to the Guilty Gear character of the same name due to him also wearing a bag on his head.
Often portrayed in fanart as actually being the ruthless influential kingpin people think she is.
Appearance
This tag implicates hifumi_(blue_archive) (learn more).