Recommendations please!

I’m a slut for the classic reincarnation, back in time, waking up in a novel, switching bodies type situations. I’ve read a lot of them and need more. Anyone got good recommendations? Even if I’ve read them before maybe I’ll find something I wanna reread. Bonus points if it’s evil twin vs nice twin, harem, main character is a dude (don’t want harem unless it’s bl for this one), or main character starts off as a cutie patootie kid.