Neutralization

Neutralization, spoken as Inshi Sōsai, is a contact-range Emitter Quirk carried by Giulio Gandini, introduced in the film My Hero Academia: You're Next. Its purpose in the story is closer to treatment than to combat.

Once Overmodification slips its leash, it rewrites Neutralization from the outside in. The rebuilt version no longer routes through the right arm at all, and its cancellation stops being temporary: it can strip a Quirk away outright and leave the target effectively Quirkless. Whether Giulio's ability stayed in that upgraded state, reverted, or vanished entirely once Overmodification itself was neutralized is never established.

Touching a target shuts their Quirk down for a time, with the effect channeling out of the user's right arm. Activation announces itself visibly, since the palm of that hand lights up a bright pale blue, and the stronger the Quirk being suppressed, the longer and more fiercely the glow holds. Bare skin is not required, as Giulio keeps a glove on the hand while using it.

Its real value lies in medicine rather than fighting. Powers that savage their own owners, Overmodification chief among them, can be held in check this way, and Giulio's intervention is what tempers Anna Scervino's seizures enough for her to lead something resembling an ordinary life.

The limits are steep. Contact has to be sustained for several seconds before anything happens. The Quirk Factor lives in the right arm alone, which becomes catastrophic when the Gollini Family raids the Scervino Household and abandons Giulio for dead, his right arm pinned and crushed beneath rubble; the ability goes with it. Exposure to Anna's Overmodification later undoes that loss, spreading the Factor through the rest of his body and putting the power back in his hands. Strength was never its strong suit either. Giulio visibly labors to suppress Anna's Quirk during her treatments, and her father openly dreaded the day Overmodification would grow strong enough to kill Giulio outright for trying.

Giulio Gandini is the sole user. His ability invites comparison to two others: the Erasure Spot wielded by Paulo Gollini, and Erasure as used by Eraser Head. The second of those differing mainly in where the Quirk Factor sits, the eyes rather than the right arm, and in reach, since Erasure works at a distance while Neutralization demands contact. Both men also had their Quirk Factors maimed by villains badly enough to render the powers useless, though only Neutralization got a second life by expanding past the injury. The right-arm conceit likely tips its hat to Kamijou Touma of A Certain Magical Index, whose Imagine Breaker cancels the supernatural on touch, and possibly to Bungo Stray Dogs and No Longer Human, a touch-based nullifier that glows the same blue and belongs to Osamu Dazai, who shares Giulio's Japanese voice actor Mamoru Miyano.