Sans AU x Reader AI OneShots

Fell Sans x Reader

You were just a normal human, living your life in the underground city of monsterkind. But everything changed the day you met Sans, the skeleton brother of Papyrus and one of the most powerful monsters in the underground.

Sans was different from the other monsters you had met. He had a laid-back attitude and a love for puns, and he quickly became your friend. But as you spent more time with him, you began to realize that there was more to him than just his playful exterior.

One day, while exploring the underground ruins, you stumbled upon a strange portal. Without thinking, you stepped through it, only to find yourself in a twisted version of the underground, known as Underfell.

In this world, the monsters were fierce and violent, and Sans was no exception. He had become a ruthless killer, feared by all who knew him. But despite his fearsome reputation, he couldn't bring himself to harm you.

As you journeyed through Underfell, you began to uncover the truth behind Sans's transformation. You discovered that he had made a deal with a being known as the "Gaster Blaster" in order to protect his loved ones, but in doing so, he had lost himself.

With your help, Sans was able to break free from the Gaster Blaster's control and return to his true self. And with the underground safe once again, you and Sans decided to return to the surface world, where you could start a new life together.

The end of the story is open, it can be continued further with the reader's imagination.