Reincarnated Into A Villain. (Nightmare x F!Reader)

You're reincarnated into Dreamtale, a girl rabbit named Y/N she's right around the same age as Nightmare and his twin brother Dream. You've read the story before, and you know what happeneds, including how many people & monsters Nightmare kills. Including you. But, in this life, you don't want to die at the hands of Nightmare, and you don't want to die with regrets again.
With the knowledge you have from you're past life, you use it to avoid the inedible.

The story of Dreamtale ISN'T MY IDEA. AS WELL AS NIGHTMARE SANS & DREAM SANS, REFERENCES TO THE ORIGINAL STORY SHOULD BE DEFNTETLY CHECKED OUT!
(also the cover I used is from the same artist as well I think.)
(UPDATES WILL BE FREQUENT. DURING HOLIDAYS.)