1. Eschatological

Eschatological: Of or relating to-
Eschatology: The part of theology concerned with death, judgment, and the final destiny of the soul and of humankind.

Dealing with the end; having to do with doomsday shit

“He was consumed by eschatological reveries; dreams of doom.”  a person who whips themselves to repent for sins (flagellation). They would likely be someone who is consumed by an eschatological ideology.
An obsession with the eschatological angle of christianity, would be an obsession with the coming of the end.

Merriam Definition:
a branch of theology concerned with the final events in the history of the world or of humankind
2: a belief concerning death, the end of the world, or the ultimate destiny of humankind; specifically : any of various Christian doctrines concerning the Second Coming, the resurrection of the dead, or the Last Judgment
‘The eschatological element that is inseparable from christianity…” Video I saw this word used in Here