Full backstory and lore of UltimateTale!Sans, includes both versions: Fanon and Canon.

In this book, you will read and find out how this anomalous soul has been born; and further beyond, as other versions, and more.

Volume 0 - Auxiliar Information: Extra, and general, canon information
Volume 1 to 4 - Fanon Backstory
Volume 5 - Canon Backstory
Volume 6 - Fanon inventions
Volume 7 - Fanon War
Volume 8 - Theories and Theory 2 development
Volume 9 - UltSans Versus Doom Slayer
Volume 10 - UltSans Versus Kratos
Volume 11 - Battles and Encounters
Volume 12 - Play Along or Stay Forever
Volume 13 - NM Cataclysm
Volume 14 - L2D
Volume 15 - Ashed's backstory
Volume 16 - Replacement

Chapter 83 - - Reject