- Joshua Steele/Grimskull
Justin's younger brother, who initially worked together with Baron Dark out of a misplaced envy of his older brother. When Justin and Dark struggled for the Lightstar Crystal, Joshua interfered. The resulting surge of power turned him into an undead creature, but where Dark and his Skeleton Warriors are pure skeletons, Joshua - who was renamed Grimskull - is still covered in flesh. Grimskull is seeking redemption by helping his family; he saw the baron's evil during the fight which transformed him. Grimskull is granted the power to travel through shadows wherever he wishes. After his transformation, he befriended a wolf, which he named "Stalker."