Ooohhh prayer stuff. That's what he means, right? Naki doesn't do any of that himself, but...it's hard not to believe in spirits and things when you kinda are one. He can remember Ishikirimaru doing prayer and purification and things like that, back at the citadel. Preventing corruption and stuff.

The look on his face turns a very little bit concerned. "...Your soul is in danger?" If they keep preaching about saving you then that must mean you're in trouble, right? Do humans work that way? Don't turn into a killer ghost, Guts!