A hentai RPG with the twist that you don't know it's a post-rapture story until the end.
>The women in the MC's life suddenly turn into monster girls/warriors/sorceresses
>isekai-ish story where there are now mobs and monsters out in the world, there are now stats and EXP
>occassionally you have to battle other people with their own party of girls
>romancing and sexual acts with your girls raises their (and your) stats and abilities
The twist:
>The people taken by the rapture were just replaced by demons in disguise, pretending their powers are fantasy
>They are grooming you into depraved acts
>All of them are working in collaboration to create the strongest sinner, one that can be possessed by the anti-christ and destroy the world
>The only way to get the true ending is the virgin route, where you are brutally decapitated for ruining their plans