My Heaven-Defying Comprehension Has Multiple Great Emperors Possessing Me?

Su Han has been in a fantasy world for a hundred years. He has no System, no connections, and no talent, a man with nothing going for him. He worked diligently for most of his life and only managed to become a disciple assigned to guard the mausoleum at the Taichu Sect. Just as he thought his life had reached its end and decided to lie flat, he was bound to the “Heaven-Defying Comprehension” System, and several unfamiliar souls appeared in his sea of consciousness. Like other favored children of fortune, I have an “old grandpa” in my sea of consciousness. Unlike theirs, a new old grandpa appears in mine every week! These “old grandpas” keep going on about “nine lifetimes in the mortal world” and “I am the Heavenly Emperor,” and insist, “Learning from me is the only right path!” On a certain continent, Emperor Lin Xiao is meditating in seclusion. [Ding!] [You are invited to join the “Good-for-Nothing Transformation Plan”!] The next second, Lin Xiao finds himself in a sea-of-consciousness world, where he sees several souls whose power is on par with his own. They're arguing and questioning everything they know. “Wait, this is really a good-for-nothing? He learned the cultivation method I taught him in just a few breaths?” “Heh, maybe your cultivation method is just too lousy. Let me try teaching him!” “This guy's supposed to be a good-for-nothing?!” After comprehending an unrivaled immortal art overnight, Su Han tentatively asks, “Senior, am I progressing too slowly?” “Ahem... Well, I wouldn't say you're that slow. Next, I'm going to teach you the real stuff!”