In this world, your usefulness & place within the thriving hero-filled society, is determined by the strength of your muscles. Nothing more, nothing less. Brainless brutes rule in this wild and chaotic era. However, enter the prodigy. He's a 24 year old mixed college student. Grey can manipulate historical figures and their strengths to fight rather than rely on the intense muscular power like everyone else.
However, this makes him an outcast, deemed "Too Weak" and "Useless" by the current society. That is, until two figures appear, and begin dismantling the strongest of the heroes, no muscle fiber at a time.