W.D Gaster.

Gaster is a calm skeleton from the underground and also one of the strongest. Gaster is a royal scientist of the past who died and came back because sans brought him back to life. Despite his calm aura about him it wouldn't wise to make him mad. Gaster uses magic known as "chroma." Where he can summon 7 skeleton hands or even 2 giant skeleton hands. And with that power he can use the power of the 7 human souls. he is also the father of sans and papyrus who he protects. He also trained Jay rose chroma magic. he is a man of mistakes but he learns from them and keeps moving further.