Haimon

Haimon is a person partially corrupted by Xenomagi, with the dark magic being passed to him when he was attacked by a wild animal that was also infected. That's also where the scars all over his right shoulder and face came from. The Xenomagi doesn't have full control over his body yet, but its influence is already apparent, with former friends of his noticing his swiftly changing mindset, with a formerly friendly, open and nigh-on pacifistic man turning closed-off, quick to anger and much more willing to resort to violence than before, though he has managed to retain enough control to not outright kill anyone...yet. Haimon isn't aware enough to have caught on to what's wrong with him yet- he knows that things have changed and he doesn't exactly like what he's become, but he has no idea why this is happening.

Eventually, the Xenomagi will completely take him over and he'll become one of its corrupt, sadistic puppets, but if the inhabitants of Earth can figure out a way to purge it from his body before it fully consumes him, there may still be hope for him yet.