Marcus is a sort of rough-n-tumble guy – currently a senior at the Academy – who has recently befriended the protagonists. He’s one of Dimitri Engel’s good friends and it seems that Marcus used to look out for Dimitri when he was a freshman. Marcus is a hard worker and is slated to graduate half a term early. He’ll probably go into the ATOG.
Marcus’s power is two-fold: His skeleton is laced with naturally occurring carbon nano-fibers and his body heals at an accelerated rate. And he has complete control over his skeletal structure and can grow and shape his bones into weapons and armor. This means that Marcus can rip his own bones out and use them as weapons – and heal the damage this causes him in the blink of an eye.