For Your Sake (Gaster!Sans X Reader)
THIS IS A SEQUEL BOOK!!! IF YOU HAVE NOT READ THE FIRST BOOK YET THEN GO FIND IT ON MY PROFILE!!!
Anyway, now for the summary:
After death, you hadn't expected much to happen. You fell immediately into a place like the void. You just wanted to reconcile for what you'd caused, but your heart had a wish of its own. You wished to turn back the clock and set things right. You wanted to make everyone forget your existence and make them happy again, even if it left you alone.
Well, you're one of the lucky ones. You're wish came true and you reset time. But not everything went to plan.