Steel

Steel is a Quirk used by Tetsutetsu Tetsutetsu.

Information
This Quirk allows Tetsutetsu to turn his body into steel. It can be used as both the strongest defense and the strongest attack.

Using his Quirk for too long will cause Tetsutetsu to suffer from iron fatigue, gradually weakening the steel's hardness.

Trivia

 * This Quirk is very similar to Hardening, but turns the user's body into steel instead of just hardening the skin. The two also appear to be roughly equal in terms of power and effectiveness.