I wonder if he's actually evil (hidden trap to his offer) or more that he was one of the 'evils' in that he basically represents 'sloth' here (i know the 10 evils don't align to the 7 deadly sins, but whatever). He's not a 'bad end' but his offer takes many people out of the progression as it offers an easy exit ramp to the madness, making it that much harder on the Joon (and now the MC) in future scenarios as there are many less people to rely on. Plus, Joon seems like the type to crash and burnout and stay here, ending his regressions early, thanks to his regression sickness.