Half-Cold Half-Hot

Half-Cold Half-Hot is the Quirk used by Shoto Todoroki.

Description
Half-Cold Half-Hot allows Shoto to generate ice from the right side of his body and flames from the left.

Half-Cold Half-Hot stems from the fusion of Shoto's father's Hellflame Quirk and his mother’s Ice Quirk through a Quirk marriage. As a result, Half-Cold Half-Hot is perfectly divided between the right and left sides of Shoto's body. This gives Shoto two powerful separate methods of combat that he may use regardless of the other to an extent, if he chooses.

For the Quirk to function properly, Shoto needs to constantly alternate the use of both his sides, heating himself with his left side after using ice or cooling himself with his right side after using fire. Overusing either side might lead to either frostbites or overheating, with possibly fatal consequences.

Usage
Right-side: Using the limbs on the right side of his body, Shoto can drastically lower temperatures and freeze anything he touches.

Shoto is able to swiftly freeze entire buildings and streets, as well as create large waves of ice instantaneously. Despite its incredible raw power, Shoto possesses great control and direction over his right side. He can restrict the ice to avoid fatally freezing someone, or use precision attacks to freeze only certain portions of a target's body.

Shoto is capable of molding the ice into certain shapes to support himself, such as protective barriers, stairs to elevate himself or a moving wave of ice for him to surf through. Shoto has many mobility options too, like stacking ice shards behind his back to propel himself forward or freezing the ground to skate on it.

Prolonged usage of his right side will lower his body temperature to dangerous levels. When this occurs, Shoto's body gets covered in frost and his ice attacks lose their effectiveness. His maximum output brings him to his temperature limit almost immediately.

Left-side: From his left, Shoto can drastically increase temperatures and release scorching hot flames.

Due to Shoto's animosity towards his father, he held off on using his left side offensively for most of his life, activating it only for thawing victims of his freezing attacks. As a result, his manipulation of the flames was rather poor in comparison to the finesse of his right side. His lack of control made adjusting to the high temperatures of his flames difficult for him.

When Shoto ignites his flames, the resulting blaze covers his arm and the left side of his head. He is able to shoot out consuming streams of fire or protective short waves of it.After upgrading his costume to help him control his temperatures, the flames only ignite on Shoto's hand, displaying more command over his left side.

Once Shoto begins to accept his father and embrace his left side, he becomes able to produce large-scale fire attacks like a wall of flame. Despite teaching Shoto from a young age that the flames he can produce are unrivaled, Shoto still prefers to use his ice more. When Shoto fights against Tetsutetsu's temperature resistant body and his ice doesn't work, he finally goes past his limit and unleashes the full might of his left side.

Shoto admits his overall control is still very poor, but the full fury of his flames are enough to set nearly all of Field Gamma ablaze. Shoto's strongest flames are hot enough that they threatened to melt Tetsutetsu's iron body. Overusing his fire can cause his body to overheat and insights dizziness that can render him unconscious if not kept in check, a weakness he shares with his father.

Fortunately, Shoto is capable of using his other side to counteract the dangerous effects of whichever one he happens to be overexerting. Activating both sides simultaneously is possible as well, but lack of practice has made this awkward for him as it dulls his movements.

By chilling the air using his ice and then heating it in an instant through his fire, Shoto can release a huge super-heated blast of flame that devastates anything on its path. Overall, Shoto's strongest attacks tend to be of an impressive scale, although that's not always a good thing, with Katsuki once noting that Shoto loses some of his precision when attempting to overwhelm his enemy.

Named Techniques

 * Giant Ice Wall (大氷壁): Shoto uses his freezing powers to generate a giant glacier-like wave of ice. He first used this move on Hanta Sero in the U.A. Sports Festival. It remained unnamed until the Final Exams, where Momo Yaoyorozu dubbed it. Shoto used a smaller variation of this move against Katsuki Bakugo, and the largest version was used to attack Mr. Compress.