Synno!Sans is a Multiverse villain that plans to corrupt all AUs and use them to build his own megaverse.
BackstorySynno!Sans once lived in his own universe, and was living a mostly ordinary life. All of this changed when Farah (Frisk) chose to play around and experiment with the coding of her Pacifist game file. As a part of this experiment, she typed the letters FFR.VOID.EXE into the coding for her game file. This string of letters caused the universe to become unstable, and slowly break apart. Synno!Sans, alarmed and distressed at what was happening, tried to save his universe by hacking Farah's game files and removing the code, but time was running out. Because of this, he hunted down Farah, killed her, and took her soul so that he'd have complete control over his timeline. Using Farah's soul, Synno was able to escape when his universe collapsed, but everyone else that lived in the universe died from the collapse. Synno!Sans, feeling that he'd lost everything, decided to find another AU to live the rest of his life in. He originally thought of living in Underswap, until he found out that since he still had control over Farah's soul, he also had control over her game files and the ability to reset. After a while, Synno!Sans hacked into the source code for Farah's game files, altered the code, and switched the RESET button to a CORRUPT button. This button has the ability to give its user control over a foreign timeline, and anyone in that timeline. Using this new power Synno!Sans set out to CORRUPT any universe he came across, and merge those universes to create his own megaverse.
Synno!Sans is skinnier than Classic Sans. He wears a black jacket with a red stripe going completely around it and the hood. His shorts are black, with red stripes replacing the original white ones and he wears black slippers. Synno is never seen without his hood and no one knows why he always wears it. He also has a large hole in both of his hands, and oddly, the hole in his left hand holds a monster soul. Having two souls makes him harder to kill. He has two stripes coming out from underneath his eyes and his eyelights (or "eyes") are red.
His trademark symbol is a circle with two triangles on the inside.
Synno's main weapon is his scythe, which is black handled with a sharp red blade. If he is able to get close enough to his opponent, he can use this scythe to launch an attack directly at their soul, which has a higher chance of killing a monster than a human. He can also send a large wave of sharp bones out of the ground by digging the blade of his scythe into the ground.
Synno!Sans still uses normal bone attacks and gaster blasters just like Classic Sans. He is also very agile, and can teleport as well. If he manages to weaken a monster or a human in battle, he can control them for a short time. He can also use telekinesis, and he can create a portal to the multiverse and travel to other universes.
Although having the ability to possess a monster soul, when weakened, he is extremely vulnerable to soul possession himself. He's also not very physically strong (muscle strong), and relies on his magic to make up for that. The events of his universe also left him a little insane and emotionally weak.
Synno!Sans became a little insane after losing his entire universe and everyone he cared about. Feeling that humans are always taking things away from monsters, he has a burning hatred for humans and if he sees one, tries to immediately kill it. He's extremely devoted to his mission of building his megaverse and doesn't like being interrupted while accomplishing it. He views any monster that is friends with a human as ignorant and idiotic. However, although Synno may put on that he likes to see people suffer, it greatly disturbs and leaves him wondering if he's really doing the right thing. Whenever these doubts emerge, he quickly dismisses them, and remembers his goal.
Synno!Papyrus: Brother. Had a big influence on Synno's life after he taught him how to be kind.
Farah: Used to be his friend. He blames her for everything that happened to his universe.
- Synno!Sans has a monster soul in the hole of his left hand, and control over Farah's soul. So technically, Synno!Sans has the power of three souls, counting the one he originally had.
- Synno!Sans gained 3 LV from killing Frisk, which grants him 40 HP
- Synno!Sans still has his love for ketchup