Sludge Villain

Nothing about this villain is solid. His whole frame is a heap of dark green sludge with the consistency of mud, produced by his Quirk rather than worn over anything, and a pair of big round eyes plus a mouthful of sharp teeth sit within the mass. Because there is no body to strike, ordinary force accomplishes nothing, a lesson Eijiro Kirishima learns when he cannot get a grip on the substance at all. Acid and heavy wind pressure are another matter entirely, since both break the muck apart and leave him coming to pieces.

Cruelty and self-interest drive him. He robbed a bank in full daylight and strolled off with onlookers watching, untroubled until word reached him that All Might was nearby. Wearing Izuku Midoriya or Katsuki Bakugo as a suit cost him no hesitation whatsoever, though the process would have suffocated either boy, and he narrated the timeline to Izuku as though it were a courtesy.

What the Final War exposes is how thin that cruelty runs once he is at risk. He kept clear of the fighting, put on a show of participating, and slipped off the moment nobody was watching. His reasoning for grabbing Hitoshi Shinso was that Gigantomachia had already woken, so there was no sense in exerting himself. Once Mina Ashido got the better of him, he abandoned the field rather than trade blows, announcing that he intended to stay with the winning side.

He first appears fleeing a bank robbery, and All Might spots him and drives him down into the sewers. Surfacing to grab a passing body, he settles on Izuku, only for All Might to arrive and scatter him with a Texas Smash before sealing the remains into a pair of soda bottles. The bottles come loose during a midair scuffle with Izuku, and the villain slips free. He finds Katsuki next and takes him specifically for Explosion.

The rampage that follows leaves the assembled Heroes stuck, since none of them can land anything useful on a fluid target. Izuku, still Quirkless, charges in anyway out of raw conscience. The villain turns on him, All Might intervenes, and a Detroit Smash finishes it. Katsuki is released and the Police Force takes the villain into custody.

He returns to circulation after the Paranormal Liberation War, freed by All For One's raids on the prison system, and throws in with the other mutants who heed the call to arms put out by the Paranormal Liberation Front. During the Final War he joins the strike on the Jaku City Ruins meant to free Gigantomachia. The Heroes had prepared for it and hit back hard, though enough Liberation soldiers slipped through to broadcast All For One's voice and rouse Machia out of his restraints.

Avoiding the fighting, the villain stumbles across Hitoshi in hiding and absorbs him, boasting to Eijiro Kirishima that he makes a far better hiding place than the middle school kid he used last time. Red Riot cannot pull Hitoshi loose from a body that slippery, but Mina Ashido drives her hand straight into the mass and pours Acid in to mix with the sludge. Panicking, he tears himself free to run, and Hitoshi's Brainwashing catches him mid-flight and stops him cold. Hitoshi then climbs onto Gigantomachia and turns him against the other villains, and the Sludge Villain is detained with the rest of the defeated.