
Does anyone know any good evil mc preferable without harem (=・ω・=)

Death Note
From the Red Fog
Brutal: Satsujin Kansatsukan no Kokuhaku
Mr. Villain's Day Off (this one is more light-hearted)
If you're ok with anime, I'd highly recommend Aoi Bungaku Series. It's a collections of stories made into anime form and from what I remember, most or all of the mc's are not good people (can't remember for sure if there was any harem, but I'm pretty sure there wasn't).
Any good recommendations where the female lead pretends to be a boy?
It can be romance or not
Will greatly appreciate itヾ(❀╹◡╹)ノ~
Here you go dear, enjoy!
https://www.mangago.zone/home/mangalist/1581724/