Zombie Virus

Zombie Virus is a long-range Emitter Quirk held by Romero Fujimi of Isami Academy High School. It exists outside the main continuity, appearing only in the anime original special My Hero Academia: Training of the Dead.

The Quirk works by exhalation rather than contact. Romero puts a pinkish gas into the air, and anyone who breathes it in is converted, which makes an enclosed space with him in it an extremely bad place to be.

Conversion is temporary but total in the moment. Those who inhale the gas take on a zombie's punishing durability along with strength beyond what they normally possess, and their bite passes the affliction to whoever they sink teeth into, so a single infection cascades outward without Romero lifting a finger. Victims are recognizable at a glance by bluish-grey skin, hollowed eyes, and a distinctive groan.

Thought is the first casualty. Cognition drops to nothing and the infected fixate entirely on chasing down and biting anyone still clean, though fragments of who they were do survive the change. A Quirk user who breathes the gas loses command of their own ability as well, firing it off at random rather than on purpose, which turns powerful students into unpredictable hazards.

Nothing about the effect spares its owner. Romero has no immunity and wears a mask purely to keep from gassing himself, and a bite from one of his own victims would drag him down with them. Whether the condition can be undone if the user stays human, or if it simply expires on a timer, has never been settled.

Two odd gaps exist in how the infected pick targets. Anyone who already looks the part reads as kin to them, which is how Toshinori Yagi walked away untouched once he reverted to his gaunt, powerless frame while the zombified students ignored him. Some restraint also survives the conversion, as Habuko Mongoose left Tsuyu Asui alone despite being turned, the two being close friends.

Romero Fujimi is the sole wielder. His outbreak sweeps through the training camp, catching the U.A. students en masse, and he is ultimately bitten by a zombified Katsuki Bakugo, joining the horde he created.