My Evil Angel (Bill Cipher X FallenAngelCat!Reader)

Y/N, a fallen angel. Able to morph from human to cat and back again. Banished from her home, Above. She is sent to Gravity Falls to prove herself. She meets Mabel and Dipper. The twins explain to Y/N about Bill Cipher, an evil dream demon. Y/N realizes this is a perfect way to win herself back into Above. After Bill finds Y/N asleep in a tree, he catnaps her. Bill explains about his plans, about Weirdmaggedon. Y/N, scared for her life and the lives of others, begs Bill to not go through with his plans. The triangle agrees, but it comes at a cost. Y/N must obey Bill and be his slave. Will she stick to the deal? Will she fall for her capturer? Will she ever get back to Above or will she cross over to the dark side?