Responses
Yeah kkamjang is Gang-nam's older brother. The dark mortal thing takes over the body of the host and the host becomes a dark mortal as well.
Since he took in all of the other dark mortals when he was possessed, when Kkamjang originally died in the 'fire' the dark mortal hivemind went to the next potential host which is Gang-nam and his brother has been trying to supress the rest of them by strengthening him and altering his memories.
Damn
Is that little dark mortal dude called Kkamjang the brother?? Because I read the whole thing again and all Kkamjang wanted was the main character to be happy and he also wanted the other dark mortal dude to call him hyung, which means something and the green eyed dark mortal said "you can't always contro us" and since the main character's brother could do it the big brother might be that little dark mortal.