Board Thread:Questions and Answers/@comment-72.64.15.52-20171014132337/@comment-2A01:CB14:A8C:A500:B9F3:B5B0:A3AB:BC5D-20171014133532

Thats because a "real" Ghoul doesn't have kagune, kakugan, insane strength or durability. It's just an undead monster that feeds on the corpses of already dead humans. So this is his take on the ghouls and you would be, indeed, infringing copyright rules if you use the same version as him.