Love For Negativity [Nightmare! Sans x Female Reader]

Y/N is a young adult in which her life went downhill. Kidnapped, she's forced to live the life for the sake of the feared King Of Negativity, Nightmare's curiosity on a thing he had just found out despite living for centuries.
Nightmare expected once he mastered love, he would use it as a massive boost for his power, keeping the young adult in miserable life.

That's what he thought it would be, Fate isn't on his side this time.

THIS STORY CONTAINS MATURE CONTENT AND TRIGGERING TOPICS.

YOU HAVE BEEN WARNED.

[This is a different take on the AUs Multiverse, which mean some character/AU may have different personality and origins.]