Stiffening


 * Not to be confused with Hardening.

Harden (硬質化) is a Quirk used by an unnamed Shikkui Makabe.

Description
This Quirk seemingly allows Shikkui to harden held objects, making them harder than even concrete. This is done by rubbing or kneading the objects together with both hands.

This Quirk has no effect on living beings.

Trivia

 * This Quirk is the inverse of Hardening, which only hardens the user's body itself.