If I made my one Undertale OC, this would be it.
His name is Ace the Skeleton.
He is Sans and Papyrus cousin, who hasn't seen them even when they were born.
Those two eyes in the bg are his different phases of battle. His Angel's Gaze freezes enemies in place, and he becomes more focused. This is usually used at the beginning of the battle.
Demon's Rage is when he is at 50% HP, and his attacks are faster, and do more damage.
His past is a mystery, and his presence is usually ignored until someone sees him.
