Half-Cold Half-Hot stems from the fusion of Shoto's father's Hell Flame 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.
Right-side: Using the limbs on the right side of his body, Shoto can drastically lower temperatures and freeze anything he touches.
This ability is very potent, as Shoto can swiftly freeze entire buildings and streets, as well as create large waves of ice instantaneously.< He also had enough power to completely freeze a gigantic Villain Bot. 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, as well as using 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. He consistently created blocks of ice behind himself to avoid being blown out of bounds during his battle with Izuku Midoriya. In that same fight, he also created stairs of ice he could run up to elevate himself. During his battle with Katsuki Bakugo, Shoto created a moving wave of ice that he surfed to recover from being thrown.
Prolonged usage of his right-side can 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.
When Shoto ignites his flames, the resulting blaze covers his arm and the left side of his head. He is able to shoot out the blaze as consuming streams of fire or protective short waves of it.
Due to Shoto's animosity towards his father, he held off on using his left-side offensively for most of his life. As a result, his control of the flames is rather poor in comparison to the finesse of his right side. His lack of control has made adjusting to the high temperatures of his flames difficult for him. It is also possible for him to overuse his left-side, but the repercussions are not currently known.
Fortunately, Shoto is capable of using his other side to counteract the dangerous effects of which ever one he happens to be overexerting. He is also capable of activating both simultaneously, but lack of practice has made this awkward for him, dulling his movements.
- Giant Ice Wall (大氷壁 Daihyōheki?): 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.