- The first time we see a fusion in action is Chapter 2, where Katzuku blasts the Sludge Villain to bits with just one explosion. By the time All Might has finished his conversation with Izuku and Katsuki, the villain is still trying to reform himself.
- Izuchako, the fusion of Izuku and Ochako. She manages to reduce the gravity of the zero-pointer, then shatters it with One for All.
- Tsuzuru, the triple fusion of Izoru (Izuku and Mineta) and Tsuyu, manages to go toe to toe with the Nomu and actually drowns it by gluing it to the ceiling above the lake. When it breaks free from the ceiling, it's still glued to the debris and falls into the lake below.
- Katzuchako discovery of their mutation is by detonating the Nomu's arm.
Awesome / Dekiru: The Fusion Hero!