Tatsumaki vs. Psykos

Tatsumaki vs. Psykos is the battle between the hero esper of the Hero Association, Tatsumaki, and the leader of the Monster Association, Psykos.

Prologue
While Psykos is sitting in her throne room, she feels large vibrations shake the entire headquarters. She wonders if Overgrown Rover has gone silent, and is shocked at the possibility of his defeat. Tatsumaki comes from the monster's side, noticing her concern and asking if she's worrying about the cadres being wiped out. Tatsumaki then asks Psykos if she is the boss. Psykos squints her eyes and levitates off of her throne. Psykos welcomes the female esper to her base of operations, and states that Tatsumaki is someone that she must take care of personally. Psykos introduces herself to Tatsumaki, explaining her position as the military advisor of the Monster Association. Tatsumaki acts indifferent, asking Psykos again if she is the boss of the association, and Psykos sadistically tells the female esper to drop dead. Psykos uses her psychic powers to pelt and surround Tatsumaki with several boulders.

Battle
As Psykos surrounds Tatsumaki with these rocks, she attempts to compact the rocks into a small sphere and crush Tatsumaki, but the female esper effortlessly breaks free, deriding Psykos for her weak psychic abilities. Tatsumaki sends several rocks flying at Psykos, who barely manages to put up a psychic barrier in time, although Tatsumaki manages to break through her psychic barrier and take the monster's arm off in the process.

Seeing the danger she's in, Psykos decides to use her maximum power and fight with her true form. As she unleashes the full extent of her power, her body increases several times in size, and several eyes begin to pop up on several parts of her body. Psykos declares herself as the superior esper and for Tatsumaki to enjoy this to her heart's content.

Psykos proceeds to use her psychic powers to surround Tatsumaki with high gravity waves, sadistically saying she will turn the esper into a dried persimmon. However, Tatsumaki is practically unaffected, mockingly saying that the gravity waves were loosening her stiff shoulders she'd gotten from switching to a new pillow. Psykos is helpless as Tatsumaki goes on the offensive and rips off all of Psykos' limbs, causing the monster to bleed profusely. After her body is ripped apart, Psykos laments how much she'd underestimated Tatsumaki's abilities until fighting her face-to-face. Psykos admits her defeat to Tatsumaki, but also says that the esper was particlarly cruel with her dismemberment. However, Tatsumaki knows the truth: what she'd fought was merely a meat puppet being controlled by the real psychic, and confidently says she will pull her real body out. Psykos is shocked that Tatsumaki was able to see through this, and states that fighting her was premature. Left with no other option, 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. Tatsumaki suggests that Orochi is engaged with one of the S-class heroes, who while nowhere nearly as powerful as her, are still quite strong according to her. Psykos ponders this possibility and is frightened at the thought of a hero strong enough to occupy Orochi and take priority over Psykos' wellbeing. Powerless and alone, Psykos attempts to keep things calm and talk for a moment while Tatsumaki prepares to search for the puppeteer of the meat puppet.

Aftermath
After Psykos is defeated, Tatsumaki searches through the labyrinth of the Monster Association to find the real psychic that was masquerading as Gyoro Gyoro. At the same time, Orochi comes across Saitama and prepares to fight him.