How about the item that begins the relic will drop from odin or behemoth fate? Like atmas, you have to keep killing him to get it?

Sounds like it might work right? :P

Next step involves running satasha normal for a 1% chance from last boss, but it only counts if you were there for the whole run. Joining a in-progress won't work. And it's like atma, so need 12 different ones. Oh, and they randomly drop the different ones, you need the full set and... doubles can drop.