According to Vita, most humans have a limit on how much they can grow. Pure-blooded humans could only get to about two hundred before they were pushed to the next level. Those with other bloodlines could go beyond that limit depending on the purity of their external bloodline, but it was usually impossible for these demi-humans to reach the peak.
And since I was part of the Abyssal Bloodline, I didn't have to worry about limits. But that didn't mean I could reach that limit naturally. Devils had a cheat-like ability to devour souls and have their soul fuel their bodies, tempering their muscles for eternity.