Phosphor

Phosphor, full name Flashfire Fist: Phosphor is a Super Move performed by Shoto Todoroki using the Half-Cold Half-Hot Quirk.

Description
Phosphor 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. Shoto uses it to protect himself from Dabi's Jet Burn, as well as using it to combine his fire and ice into his hands and hit Dabi with it.

Trivia

 * Upon first utilizing the Phosphor, Shoto’s body resembles his father’s second hero costume.
 * Phosphorus is a chemical element that exists in two major categories, White Phosphorous and Red phosphorous. White phosphorous emits a faint glow when exposed to oxygen at a cold or room temperature. Red phosphorous is created due to a chemical reaction that occurs when White phosphorous is heated to 250 degrees Fahrenheit (121 degrees Celsius). Therefore, the super move’s ability to combine both the fire (signified by Shoto’s red hair side) and ice (Shoto’s white side) is similar to the chemical element.