Izuku Midoriya vs. Muscular

Izuku Midoriya and Kouta Izumi vs. Muscular is a battle fought between hero-in-training Izuku Midoriya, civilian Kouta Izumi, and Villain Muscular.

Battle
At the cliff, Izuku appears and saves Kouta from Muscular's attack. Izuku concludes that no one can help since his phone is broken and the location he is fighting in is secret. With no other choice, Izuku activates One For All Full Cowl and prepares to fight the villain who murdered Kouta's parents.

Before the villain can attack Kouta, Izuku jumps at Muscular using One For All Full Cowl, telling him that he is the one at fault. Izuku analyzes that the villain's speed surpasses his own and the only slight chance of victory is to close their speed gaps. Izuku punches Muscular with his broken arm, trapping it between the villain's muscle fibers. Muscualr mocks Izuku for thinking that his plan to put them in a position where speed doesn’t matter will work since his inferior strength won't save him. However, Izuku tells Muscular that his job as a hero is to put his life on the line for the sake of others; with no other choice, Izuku decides to unleash his Quirk's full power: One For All 100%.

Izuku uses One For All 100% against the villain, which blasts Muscular with great force into the cliffside and also partially destroys the cliff due to the great impact. Kouta is sent flying away, but Izuku manages to grab Kouta’s shirt with his mouth and drags him back onto the cliff. After apologizing, Izuku decides that they should quickly escape while the villain is incapacitated. However, Muscular used his Muscle Augmentation to reduce the impact of Izuku's One For All 100%  Smash, although Izuku's attack did injure the villain. The villain compliments Izuku for his strength while Izuku is in disbelief that the villain is still conscious even though he used the same output of power as All Might. Izuku tries talking his way out by asking the villains' objective, but he receives no answer from Muscular who puts on his serious eye.

Izuku orders Kouta to grab on to him; Izuku uses One For All Full Cowl to jump and run away from the villain. Izuku manages to avoid Muscular's first attack, but barely avoids the villain’s second strike which sends Izuku and Kouta tumbling to the cliff again. The heavily injured Izuku thinks that getting back to the facility where Shota could erase the villain’s Quirk is a good plan, but starts to doubt the plan due to Muscular’s speed surpassing his own. Izuku quickly forgets about the plan considering the grave circumstances he is in and decides that he has no choice but to defeat Muscular. Izuku tells Kouta to run back to the facility as fast as he can the second he clashes with the villain. Izuku uses 100% Detroit Smash against Muscular which keeps him at bay. The villain begins overpowering Izuku's attack and begins pushing him into the ground while demanding blood and death. Izuku is barely able to hold back Muscular’s strength and is shoved into the ground by Muscular. Suddenly, Kouta blasts water at the villain, demanding that he stop. However, the villain says that he will kill Kouta after he is done with Izuku. Furious, Izuku refuses to let the villain kill Kouta and begins pushing back the villain, eventually pushing the villain off him. Izuku uses 1.000,000% Delaware Detroit Smash against Muscular, a powerful smack with incredible force that smashes Muscular into the cliff. Muscular's artificial eye pops out and Muscular becomes incapacitated due to the great force of Izuku's attack. Izuku roars with triumph.

Aftermath
The defeated members of the League of Villains are arrested.