Picking up from the end of the first season of Isekai Quartet, Demiurge encourages Ainz to take the opportunity to strengthen Nazarick by recruiting from the other groups. They offer a position to Tanya, which comes with the requirement that she accept giving up her humanity and be turned into a demon.

Tanya is sent to New World, and bla bla bla. Rate M for bloodshed.

The gods, in their ever-increasing hunger for faith, decided to enact the biggest miracle ever bestowed on man, making the Empire disappear. And with the Empire now in a new world, the time for true conquest is to begin and let the humans rule the world. Yet, a certain magic caster appears on the same day...

The fatherland gets sent to the new world. I do not own Youjo Senki or Overlord. This was transferred over from wattpad

Being X failed at making Tanya see it as god, so when Tanya is about winning the war it sends her to the world where magic is more real. Fortunately for Tanya, Being X is generous enough to give her its blessing. However, is it enough for Tanya to survive if she crossed path with a certain overlord? And what if the one who sent player to NW is Being X itself?