Thread:TheDigger1/@comment-27109830-20180109181321/@comment-26220697-20180112221418

Timid high school students who became involved with an invasion of Earth by a series of supernatural beings who wish to exterminate humanity, parasites and demons respectively, and hide themselves by killing and taking over the bodies of humans. When these two were almost taken over by one of these creatures, they somehow managed to keep control over their bodies and bonded with said creatures in the process. This slightly altered their personalities, making them more confident and cocky, while also granting them superhuman abilities. Using these new powers, they decided to fight the monsters in secret, while also undergoing inner turmoil due to their hybrid natures, such as fearing over losing their humanity for good, or wondering if humans are even worth saving. Both come from incredibly gory and disturbing series, and since Devilman was what popularized this kind of manga in Japan, it's possible Parasyte was influenced by it in some ways.