Phosphor

Flashfire Heatfist is a Super Move performed by Shoto Todoroki using the Half-Cold Half-Hot Quirk.

Description
Flashfire Heatfist allows Shoto to channel both halves of his Quirk on either side of his body, effectively giving him two Quirks.

This move is first developed during a training session between members of Class 1-A in a U.A. courtyard. It is described by Shoto as his body coming together "as one," as well as creating "a body even Dabi can't burn."

This move gets its name when it's used against Dabi during the second War.

Trivia

 * Flashfire Heatfist's English name is similar to Endeavor's signature technique, Flashfire Fist, that both Shoto and Dabi both know how to use.