Heroes vs. Hundred-Eyes Octopus

Heroes vs. Hundred-Eyes Octopus was the battle between several A-Class heroes, Flashy Flash, and Tatsumaki and the Demon-level mysterious being Hundred-Eyes Octopus of the Monster Association.

Prelude
The Monster Association begins its attacks on the human cities, and Hundred-Eyes Octopus is one of the monsters sent to I-City to destroy it and kill its populace. The Hero Association quickly dispatches several heroes to take care of the monster.

Battle
The first heroes to arrive at the scene are Death Gatling, Butterfly DX, and Bone, who attack Hundred-Eyes Octopus while it's consuming a building. They fan out and attempt to attack the octopus in its blind spots. Unfortunately, it fails miserably and the three heroes are swatted away.

A few more heroes are deployed to take care of the octopus, such as Bunbun Man, Funeral Suspenders and Battery Man, but all are easily defeated. Hundred-Eyes Octopus notices Red Muffler and swings several buses at the hero to kill him. Red Muffler sits helplessly, but he is saved by Bone. Bone and Red Muffler grab the unconscious heroes and begin running, with Red Muffler noting the power this monster has. Bone analyzes Hundred-Eyes Octopus's abilities, noting that as its consumed buildings, its become larger and more powerful, and with its multiple eyes, possesses omnidirectional vision. However, Bone is not afraid. As Bone prepares to fight the monster, he dreams of the legend that will surround him after defeating Hundred-Eyes Octopus. Bone tells Red Muffler that he's fortunate because there's a milk truck that's been spilled over. He begins to drink the milk while informing Red Muffler of his high bone density, and that after drinking milk, his bone density will increase for a short period of time. After drinking multiple bottles of milk, his bone density quadruples, but unfortunately, Hundred-Eyes Octopus slams the hero into the ground, breaking all of his bones.

Coming in from behind Red Muffler is Death Gatling, who also survived Hundred-Eyes Octopus's attack and managed to get reinforcements to fight the monster. The heroes that came are Butterfly DX, Smile Man, Narcisstoic, Peach Terry and Chain'n'toad. After studying Hundred-Eyes Octopus and its movements, he determines the monster's weaknesses, so Death Gatling tells the heroes to target its eyes. Red Muffler is confident with so many A-Class heroes here to fight Hundred-Eyes Octopus, but before the heroes can attack, they're told to stop by a new hero: Flashy Flash. The hero tells the others that if they attack the Demon-level monster with "half-assed" attacks, it will only become angrier and cause collateral damage, and derides the heroes for not even realizing this. Death Gatling asks Flashy Flash how he plans to defeat it himself, so the hero tells Death Gatling to shut up and watch as he does.

Flashy Flash mocks Death Gatling by saying that eyes are weak spots for all animals, and no fancy analysis was required to realize that. Smile Man suggests a coordinated attack, but before he can even finish his sentence, Flashy Flash blitzes forward, creating large shock-waves in the process. He proceeds to stab Hundred-Eyes Octopus in one of its eyes with his katana. He continues doing this with the rest of his eyes in a very short period of time, shocking all the heroes watching. Flashy Flash jumps into the air and stabs the final eye, while the rest of the eyes simultaneously spurt out blood. Blood spills all over the city, and Flashy Flash flicks the blood off of his cape. Red Muffler is amazed by the S-Class hero's power and is confident the battle is over.

Alas, this is incorrect, as Hundred-Eyes Octopus proceeds to flail around, seemingly gaining even more energy now due to its anger and pain. Red Muffler tells Flashy Flash that his actions only made the octopus even more violent, which is exactly the same thing he derided the other heroes for attempting to do earlier. One of the monster's tentacles almost hits Red Muffler, but Death Gatling steps in and shoots the tentacle. Flashy Flash decides to finish the monster off and prepares to use one of his special moves. But before he can do anything, Hundred-Eyes Octopus is suddenly lifted up into the air.

The heroes realize Tatsumaki has arrived to deal with the monster. The esper uses her powers to crush the octopus, squirting blood in the process, some of which almost lands on Tatsumaki but is prevented from doing so by a psychic barrier she puts up. Smile Man remarks that she's crushing the octopus like an empty soda can. The esper thrusts the monster into the ground, having compressed it into a giant ball and effectively killing it.

Aftermath
Tatsumaki proceeds to deride the other heroes for not being able to deal with the threat while they're so short-handed. Narcisstoic tries to say they were already dealing with the threat, but Butterfly DX tells him to stop, saying it's no use. Tatsumaki next directs her insults to Flashy Flash, telling him that he should start acting like an S-Class hero and do his job properly. Flashy Flash instantly yells back, insulted that she snatched the prey he'd cornered. The other A-Class heroes urge him to stop, saying they have no desire to be dragged into their quarrel. Tatsumaki leaves with saying the heroes are beyond useless, and Flashy Flash leaves with frustration over so many heroes sticking their noses where they don't belong. As Death Gatling watches the heroes leave, he expresses internal frustration of their failure to defeat Hundred-Eyes Octopus, remarking that the A-Class heroes lost serious face today.