Scales

Hiryu Rin of Class 1-B carries this Transformation Quirk, which first appears in Chapter 25 and reaches the anime in Episode 16. Its listed range is variable, and that flexibility is the entire point of the power.

The plates it produces look like a reptile's, hard and pointed enough to injure anyone who brushes against them. Growing them is not free. His costume notes record that the process draws on collagen and calcium, tying the ability to real biological cost.

Hiryu's kit is rounded out by his Scale Gauntlets, hardware that collects the plates his arms generate and spits them out in a rapid stream closer to a gatling gun than a thrown weapon. The gauntlets sharply raise his ceiling as a ranged fighter.

The Quirk can cover any part of Hiryu or all of him, and the resulting shell serves two purposes. Left in place it blunts incoming attacks. Detached and fired, the same plates become cutting projectiles with enough force to shear through Vines and mar solid metalwork.

Defensively it has a clear ceiling. Compared to something like Hardening or Steel, the protection is second-tier, since a hard enough blow simply knocks the plates loose. The offensive side has its own gap: speed beats it. Tsuyu Asui gave Hiryu real trouble by leaping around faster than he could line up a shot.

Three named finishers exist. Sprouting Scales, or Garin, routes a barrage through the gauntlets at a chosen target. Reverse Scales, Gekirin, flips the plates so their points face outward like a coat of spikes, and remains unseen in action. Within One: Scale Carapace, Fukuchū Rinkō, triggers growth across every inch of skin for a complete suit of armor, and has likewise never been demonstrated. The Reverse Scales name nods to Japanese dragon lore, where a beast was said to bear one plate turned against the grain of all the rest.

Hiryu Rin is the sole wielder, and he plays the Quirk situationally rather than settling into one mode. When an opponent is within reach he trades blows directly; when they are not, he opens fire, moving between the two as the fight allows. If he reads an incoming counterattack, he shells up in time to absorb it.

His marksmanship deserves particular note. During the Joint Training Battle he used Sprouting Scales on a wayward pointer belonging to Denki Kaminari, one that had lodged itself on Jurota Shishida, striking the tiny mark from a real distance without wounding his teammate.