Myriad Apocalypse's

There were too many worlds left abandoned and on the cusp of destruction in the wake of the higher beings. So in order to save the core souls of those worlds someone was given the power to save the core souls of those worlds so they could be recreated. "What the hell do you mean my isekai adventures are just going to be apocalypse worlds!?" A minute later. "So I get to save worlds and I get a whole Cyoa to fill out to make my life easier and I will inevitably get a harem? Alright, deal!"