Chapter 108 (Online): Orochi vs. Saitama

Saitama brushes off the confrontation by describing himself as nothing more than a resident from up top. Orochi charges with its horns and gets nowhere. Piecing things together, the beast realizes the tremor it sensed earlier came from this stranger, someone absent from the Association's list of threats, and it concludes that letting him live could spell disaster. Saitama, unbothered, guesses the creature is not alone down there and insists he is only defending himself against the rest of the monsters. Orochi answers with a gout of flame that Saitama barely slips past.

Overgrown Rover stirs awake, and Orochi commands it to finish the trespasser. The beast instead identifies the one who had beaten it and bolts. Baffled, Orochi asks what became of Rover, to which Saitama flatly replies that he thrashed it. Now certain he is dealing with a monster, Saitama readies himself. Orochi, connecting him to the falls of Gouketsu and Elder Centipede, grows thrilled and shifts into a sleeker, more human-shaped body, eager to test what such a powerful opponent can do.

Saitama counters that every so-called ultimate being talks the same way and still crumbles to one strike. Orochi lashes out with the dragons sprouting from one arm, all cut down instantly. The dragons of its other arm then loose a colossal bolt of electricity that rips the ground open into a vast tunnel, startling the S-Class heroes who scramble to shield themselves. The blast even tears through a subway line, leaving a bewildered train driver to watch Saitama streak past. A single punch shatters Orochi, and its broken head asks what could have hit it. Saitama calls it a normal punch, and Orochi, finally understanding fear, tumbles into the darkness below.

Orochi identifies Saitama as an unlisted threat and begs to eliminate him before he becomes dangerous. Overgrown Rover recognizes Saitama and flees rather than obey. Orochi transforms into a humanoid shape and unleashes a massive electrical beam that carves a tunnel through the base and reaches a surface subway line. Saitama ends the fight with one plain punch, destroying Orochi and sending its remains falling into the abyss.

This online edition, titled Orochi vs. Saitama and matching that name in the Viz release, is the 108th chapter within the Monster Association Arc. It has no webcomic counterpart. The bout it depicts is catalogued separately as the Saitama versus Orochi battle. The narrative leads into the online Chapter 109, Fake.