MHA Story And Quirk Ideas

Story: Muscle Augmentation

Izuku's quirk is Muscle Augmentation. It's the exact same quirk Muscular has in canon, however it got Izuku'ed. He figured out that he could condense his muscles to make smaller, more compact muscles that hug his body and are much stronger as well as tougher to cut into or break. He also figured out that by controlling a single fiber, he could use it as a whip or use it to trip opponents.

Since the anime never really did I'm going to make up some things about the quirk.

Muscle Augmentation is an accumulation/stockpile quirk. Izuku gets more muscles by working out. Once his body hit peak human and physically could not build more muscle it started to build muscle outside the skin. So the more Izuku works out the stronger, tougher and more numerous his muscles become. As a result Izuku's body looks like it were chiseled out of marble.
Due to the nature of the quirk, it makes it completly safe to work out as a child.

Izuku's appendix is a Pocket Dimention that holds any and all extra musculature that cannot be contained within his skin while not in use. If damaged or ruptured the muscles contained within will spring out and stay out until the Appendix is healed, [which takes roughly a month if completly destroyed] so Izuku takes priority to protect that area of his body. He also never tells anyone about that weakness, claiming the time he found it out as a "Quirk Malfunction".

Story Aspect

Muscular doesn't exist. He is replaced by a man of the same name and biology, however with a Quirk that allows him to cut out and attach other people's muscles to himself. The process is deadly and very painful if the target is alive, as he needs to literally cut out their muscles with a knife. Dur ti this his victims can never have open casket funerals as the body is gruesome to look at. He enjoys targeting living victims because he loves hearing their screams of pain and agony. When using his quirk he looks like a very bloody patchwork of diffrent color muscles and tendons, ranging from pink, hot pink, blood red, muscle red and corpse white. Once deactivated, the stolen muscles shrink to a microscopic level, and when activated they grow to meet his needs. His villain name is Patchwork, and he is an S rank villain.

OFA and Muscle Augmentation

These two quirks work magnificently together. One for All needs muscles to work, and Muscle Augmentation creates muscles. Muscle Augmentation can already reach levels rivaling that of All Might's 100%, or at least being able to withstand it. Now imagine the sheer force that would be generated with both of them together! Not to mention that it would fix the issue of OFA getting too strong for the human body to handle later on, as you could just grow more muscles to withstand it! I honestly don't know why people haven't realized the potential the two of them have combined!