UnderTale AU (Sans X Noble Reader)

You will need to read this for the backstory thought it will be in the info page too but there will be more to it;
You are a member of a noble family known for their magic, the LongHeart. The LongHeart's was the ones who sealed the 'monsters' underground with that spell, but that was a long time ago. There was 7 of them then, but that was a long time ago. The people of the kingdom have forgotten all about the monsters, even the LongHeart family had forgotten them...Almost at least. "Legends say that those who climb the mountain next to the town never return." That was the last time your mother said that story to you and your little brother before she passed away the next day. She had fallen sick two weeks before Mix's birthday and died the day after. (Mix is the name of the little brother) Two years later, your dad was called to meet the king but will on his way there he was killed by bandits that go by the name of Red Dragons. (The bandits were found late that same day and killed by the order of the king)