Ken Ishiyama

Cementoss is a Pro hero and one of the staff at Yuuei.

Appearance
Cementoss appears to be a humanoid block of cement.

Ultimate Space & Jams Arc
At the end of the arc, he appears with alongside the other Pro Heroes. When Eijirou Kirishima runs over to see if All Might was ok, he uses his Quirk Cement to create a long cement wall to stop him from seeing All Might's true form.

Quirk
"Cement" - Can create cement by touching surfaces.

Trivia

 * He's a big fan of All Might