Mushroom

Mushroom, read as Kinoko, is a long-range Emitter Quirk belonging to Kinoko Komori of Class 1-B. It arrives in Chapter 199 of the manga and in Episode 93 of the anime. Rather than striking a single target, it turns terrain itself into a hazard.

Komori releases fungal spores out of her body and pushes them outward. Anywhere those spores settle on something solid, mature mushrooms sprout almost immediately. The receiving surface hardly matters: open ground works, her own skin works, and so does another person's body. Damp air makes the spread substantially easier.

The Quirk is indiscriminate, which is its central problem. Spores land on friend and foe alike, so teammates have to be treated with an antifungal spray in advance or they will sprout too. Countermeasures are straightforward for anyone who knows them, since ethanol and other fungicides kill the growth, and open flame burns the spores while they are still airborne. Left alone, the mushrooms simply die off after roughly two or three hours.

Kinoko Komori carries at least two spray bottles into the field, using them to raise local humidity so her spores travel farther and faster, which is how she buries an entire area in fungus in a matter of minutes. Cornered, she can force a mushroom to bloom inside an opponent's throat and choke them out. Her named technique, Splitgill Lung Strike, does exactly that with Schizophyllum commune, suffocating the target and pinning them in place.

She pairs unusually well with two classmates. Black benefits from dark mushrooms that double as concealment, while Comic can pump humidity up through the right onomatopoeia and accelerate her growth rate. The species she has been shown cultivating include black wood cauliflower (Sparassis), yellow knight (Tricholoma equestre), enoki (Flammulina velutipes), inky cap (Coprinopsis atramentaria), and split gill (Schizophyllum commune).