TheJiujitsuGuy
you could also add: Black Lagoon, Jormungand, the blacklist, Boss In School, God Of Blackfield, The Fruit of Grisaia, The Breaker manhwa, Veritas manhwa, Girls of the Wild's. While these if you want to add the supernatural side: The God of High School, Noblesse, to love ru, Rosario + Vampire, Sister's Testament New Devil, DxD, Kaze no Stigma, Full Metal Panic!, Seikon no Qwaser, Campione.
Will he be able to get the demon back/Demon Face both on his brain and on his brain (I think that's why Yujiro is a genius and can learn everything practically instantly since they say his strongest part is his brain)? There would have been good jojo too (besides learning ripple and getting a stand by defeating a pillar men he could get their powers if I understand correctly) the problem is that they are already finished unless you go back in time.