Cement

Written セメント and read Semento, Cement is the power behind the Pro Hero Cementoss, Ken Ishiyama. The classification is Emitter, and the range is contact only. Readers first see it in Chapter 21, with the anime following in Episode 13.

A related power exists in Earth Flow, which operates on the same principle with a different medium, working soil rather than concrete.

Touching a cement-based surface hands Ken control over it. Creation is off the table, so nothing new comes into being; he reshapes what is already there. Whatever state or form the concrete happens to be in, he can mold it however he likes and turn it into a weapon, but only while contact holds. Under favorable conditions, opponents strong enough to smash concrete outright still find themselves buried by the sheer volume of it.

This makes geography decisive. Urban terrain is saturated with his medium, giving him an enormous edge, while rural settings with little or no concrete strip him of most of his fighting power. The anime adds a visual cue, tinting his hands with a faint green glow while the Quirk is active.

Ken Ishiyama uses Cement offensively and defensively alike, raising enormous concrete walls to box enemies in and cut off escape. Away from combat, he builds. Gym Gamma is his handiwork, and so is the stage where the U.A. Sports Festival held its combat rounds. Elaborate structures take him only minutes to assemble, which speaks to how thoroughly he has mastered the power.

His skill shows again during the Paranormal Liberation War, where he rips the entire front off the Gunga Mountain Villa and lays its interior open.