Starphase, Steven A.

Seemingly laid back, he gives off an air of a suave businessman, always with a quip or sardonic comment to make about the situation. When crossed, however, Steven shows a ruthless side, and is not above using his connections to make "problems" disappear.

Esmeralda Blood Freeze (エスメラルダ式血凍道) is his fighting style. Steven's ability allows him to decrease the temperature of his blood in order to freeze targets. His techniques are spoken in Spanish.

(Source: Blood Blockade Battlefront - Kekkai Sensen Wiki)