am I tripping? I feel like this has been uploaded before.

Yeah! I thought so too!!
Especially when i see those horns and nipples ლ(´ڡ`ლ)
But i'm scared that i might be wrong. Maybe i read on mrm and not here ╮(￣▽￣)╭

Idk he kinda looks like cain from dear door?

Nope.
It turns out I've read it on mrm before. ╮(￣▽￣)╭

https://myreadingmanga.info/p-point-nanji-ware-wo-kouryaku-seyo-eng/