BlindProphet
After losing his mother, Percy Jackson is forced into Bruce Wayne's custody - a stranger with too much power and too many assumptions.
The Batfamily takes one look at the silent, hooded teen and decides he's a cultist in need of saving.
Now Percy is grieving and cornered, stuck in a house full of vigilantes who can't decide if he's a threat, a victim, or something in between.
the cult idea is from Another Cult Sibling by Arazog on Ao3. It's great and I really recommend checking it out :3