Limitless Leveling: My Weakness is UNKNOWN.

Aaron was considered an abominable existence by his Father. Unlike his stepbrother, who inherited the physique of a warrior, Aaron was born with nothing but the frail, ordinary body of a slave, which he inherited from his mother. He was considered utterly useless for most of his life. But then, disaster struck. An unacceptable truth was revealed: the world was not alone—it was one of seven. And there was a brewing war amongst the seven Gods. As war loomed amongst the Seven Gods, they abandoned their creations and lifted the seals placed upon every being they had created. In no time, humans and creatures with strange powers began to emerge. Abilities awakened. And with every ability came a weakness—a fatal flaw that kept even the strongest in check. Every being with powers had one. Even powerful adversaries. …Except Aaron. He possessed a power that defied limits and had no weakness. Because of this, he gained the attention not just of powerful beings, but of existences dreaded even by the Gods, placing his world in more danger as he struggled to protect a world he never truly loved. Disclaimer: The MC grows to be immensely more powerful than his counterparts. In fact, he's close to being called overpowered… But he struggles. He battles in situations where, despite all his power, his life is sometimes on the line. So, if you're looking for an MC who defeats his foes in seconds… Sorry, but this might not really be for you.