Bill Clave

You are the daughter of Stanley Pines, he had you with a woman in Las Vegas, Asus 50 years had been a slip and he did not know of your existence until you were 5 years old and your mother abandoned you at the door of Stan's cabin with a letter explaining that he was your father, since then he took responsibility for you and you loved each other very much, now at 20 years old, you helped him with the cabin and took care of Mabel and Dipper.
Throughout the summer you had met Bill Key several times, you had faced him and defeated him along with Mabel and Dipper, he always got upset when he saw you, he couldn't maintain his physical form in your presence, when the raromajedon finally began and he felt your arrival a shiver ran through his body and he decided to make a deal with you to end the raromajedon, you would have to go with him since he wanted to understand why you upset him so much

"So? Do you accept the deal?" he asked, stretching out his hand towards you.

Stan: "Don't do it little girl! Please get away from him!" your father screamed terrified.