MADK
https://www.mangago.zone/read-manga/madk/
I Got Caught Up in a Magical Youth
https://www.mangago.zone/read-manga/i_got_caught_up_in_a_magical_youth/
they probably don't fall under monsterfuck but uh take them.
Lol I have a list of this
https://www.mangago.zone/home/mangalist/2417119/
The degree of how inhuman they are varies
madk it has more mindfuck (in a sticky weird not okay feeling kinda way) than monsterfuck goodness LMFAOAAOO
i haven't read it yet so idk but I've heard stuff about it so i recommended it lmaoo
i watched venom the last dance and now i am in need of some nice monsterfuck yaoi... decent plot would be a Very nice bonus so if you have ... please share