Chapter 72

"Monster Transformation" (怪人化, Kaijin-ka) is the 72th chapter of the One-Punch Man manga series.

Summary
It is revealed by the Super Fight Announcer that Gouketsu is the champion of the first Super Fight. Gouketsu then explains his disappearance that occurred several years ago. Orochi fought and defeated Gouketsu, but he spared Gouketsu's life in exchange for Gouketsu's service towards the Monster Association. Gouketsu accepted the deal because the Monster Association also offered him immense power with Monster Cells. After finishing his story, Gouketsu offers the martial artists a choice to either become monsters or die by his hand. Rosie rushes to eat one of the cells and then proceeds to attack an injured Dave. Choze snaps Rosie's neck and proceeds to eat one of the cells for himself. After transforming, Choze decides to knock Jakumen out of the ring. Benpatsu, Hamukichi, and Volten follow suit in eating the cells. Suiryu asks one of the civilians if he can go on a date with her if he beats up the monsters, which she nodes to. With new motivation, Suiryu prepares to fight.