About him and his AU
Bill!Sans is the Undertale version of Bill Cipher. This AU is referred to as Gravitytale or Underfalls. This AU can be taken in two ways. The first is where Bill Cipher has possessed Sans, the second is that it is a normal AU where Bill is Sans in the first place. This AU is not a very well-known AU. This version of Sans has the powers of Bill Cipher. He is incredibly strong compared to any other Sans. His brother is known as Will!Papyrus which is Reverse Bill!Sans and is the only other person in his AU.
Bill!Sans is the judge of the multiverse, even overpowering Ink!Sans. He is always after the multiverse rift that Ink tries to protect at all costs. If he manages to break it then what keeps all the Undertale AU's separate will break allowing any character to go into any AU. If this happens, Bill!sans's nightmare realm will be open, allowing him to unleash Weirdmageddon across the multiverse. He will also try to make deals with the evil versions of Sanses to help him achieve his goal. Examples: Murder!Sans, Killer!Sans, Cross!Sans, and Error!Sans. This Sans does not like generally killing anyone. He only likes to see them suffer. He will fight back in self-defense or to get something he wants, but his ultimate goal is to get the rift from Ink.
When going to other AU's
Bill!sans often goes to other AU's to be an annoyance. This Sans normally shows up during a genocide run and will help whatever Sans that is there. Whenever he teleports out of an AU he says "You're all pixel characters, without real feelings, send Temmie to college BYEEEEE!".
- He likes to spend time with Fresh!Sans because their personalities complement each other.
- Unlike other Sanses, he drinks grape juice, not ketchup.
- This Sans can warp reality to his liking.