Saitama vs. Orochi

Saitama vs. Orochi is the battle between the B-class hero, Saitama, and the leader of the Monster Association, Orochi.

Prologue
After Psykos is defeated by Tatsumaki, Psykos calls out to Orochi to save her. Tatsumaki remembers that name mentioned before, and Psykos asserts that while she's the military advisor, Orochi is the boss of the Monster Association, and that even as his creator, she cannot accurately gauge his power. Psykos wonders why Orochi is not coming to assist her, for she managed to obtain absolute control over him from years of brainwashing during his transformation as a monster.

Unbeknownst to her, Orochi took notice of Saitama being able to defeat Overgrown Rover. Using his dragons, he lifts himself up several floors of the Monster Association Headquarters and spews cascades of fire that cover his entire chest, while several dragons slither out of his body as well. Saitama goes over all of the odd things he's seen so far: a pair of streakers, a dog, a cat, and now, this monstrosity, and wonders how something like this could live underneath his house. Orochi says he doesn't know how Saitama managed to get in, but he can tell that Saitama is not useless trash that can be ignored, and prepares to fight the hero.