Atomic Samurai vs. Haragiri

Not everyone is as stupid as you. Atomic Samurai vs. Haragiri was the fight between the S-Class hero Atomic Samurai and the monsterized swordsman Haragiri of the Monster Association.

Prelude
Atomic Samurai calls for a meeting with the Council of Swordmasters to ask them for assistance in finding and killing Garou. Haragiri mocks Atomic Samurai's plea, interrupting the conversation and telling everyone that the council's true purpose is to improve swordsmanship, and that meetings such as these are irrelevant and unnecessary. He reveals that he's become a monster and joined the Monster Association. He then throws a bag of monster cells and orders everyone to eat them, change the name of their council to the Council of Sword Demons and go beyond good and evil to reach new heights.

Atomic Samurai mocks Haragiri for how far he's fallen, but Haragiri boasts about his newfound speed and that regardless of Atomic's decision, he is to kill the hero. He gives the council members 3 seconds to eat the cells or die, and Atomic Samurai says no one is stupid like Haragiri, which enrages him, causing him to attack Atomic Samurai.

Battle
Out of anger, and in an attempt to catch Atomic Samurai off guard, Haragiri unsheathes his sword and tries to cut Atomic Samurai's head off. But before the monster's sword could even connect, Atomic Samurai had already taken out his sword and performed his Atomic Slash at speeds Haragiri wasn't able to react to. The monster is then cut into hundreds of little pieces, with his sword being destroyed in the process as well, marking the death of the fallen swordsman.

Aftermath
Haragiri is killed and Atomic Samurai decides to strike the Monster Association headquarters, along with his pupils Iaian, Okamaitachi, and Bushidrill. He searches through the mountains with his disciples for any hint of the Monster Association and destroys any monsters they encounter.