The nig-o dude probably doesnt exist and the MC got dissociative identity disorder from the PTSD and will blame all problems he cause on his evil twin.
Feels like a story Hiroya Oku would write since it's kind of a fucked up concept to begin with and there's lots of room for chaotic darkness and/or comedy.
Also I lol'd at the TL note telling us not to say it. Nigo, pls.