Why must sin taste so bitterly sweet (fyozai)

Fyodor grew up his entire life being warned of the horrors of sin and those who carry it within them. Sin is evil, it is all that is wrong in the world, so why on earth is he so drawn to the sinner that drips with it in the basement.
OR

Fyodor lives in a heavily religious cult like village out in the Russian countryside and usually dealing with the sacrifices is one of the most tedious tasks that plague his existence but this time around it appears to be something different.
OR

Fyodors cult/village kidnaps dazai as their next sacrifice, Fyodor is assigned to keep him alive while they prepare him over the course of a month for the ceremony and he ends up developing a fascinating curiosity with their newest sinner who didn't seem to mind being there at all.

No abilities au btw

(Originally uploaded to ao3)

Cover art is not mine as always x

Irregular updates <3