The Abyss Within (Undertale AU Fanfiction Based Off A Comic Dub)

AbyssTale Sans had a lot of problems back then. Even now, he still does. But his soul was very unique in a way even his own father couldn't describe... he was valuable in a way. The thing that kept him going was how he EVOLVED in life. He still had a lot to learn. He got a book from someone that had all the information about "AU's". Every single one... it was also very valuable. What happens when he has to keep guard of people kidnaping him, persuading him, and trying to steal his book? Will he join nightmare's side or still be stubborn? How bout his other friends? What exactly is he valuable for..? Find out.