You've been isekaied into a fantasy to kill the Demon Lord!...Except he's already dead by your hand...And every guy wants to have sex with you...And you have no idea where you are or what's going on.

It's a story as old as time, you're summoned to an isekai world and the goddess gives you a special power, blah blah...Instead of those other idiots, you decide to ask for a specific power... "Let me change reality on a whim."