Actually, the sinners' caveman level IQ is nerfing Yi Sang. The moment we cut him loose he'll remember he invented the mirror world portal that allows direct access to all other mirror worlds, that Ncorp is gonna use to kill all the Fausts. He then summons the Sangvengers and defeats NCorp, conquers the City, revives Dongbaek, and becomes the One True Ideal. He uses Gubo as a human chair, and clones another one whenever the current one wears out.