Hardening

Hardening is a Quirk used by Eijirou Kirishima.

Description
The quirk allows Kirishima to harden his body. It can be used as both the strongest defense and the strongest attack.

However, the upper limit of the quirk is seen to be physical fatigue accumulated by the amount of damage taken, as shown in the Sports Festival Battle between Kirishima and Bakugo where the latter used a series of Explosion quirks to cause further damage to induce fatigue on Kirishima.