Formerly known as William, he is now often called Error404. He is a male monster. Among the Undertale AUs, he is an incredibly powerful Sans. Error404 is the God of the Multiverse. His birthday is December 20th, and he is reportedly 185cm tall. Error Sans is his apprentice, and Alpha Sans is his brother. Error404's attack methods and abilities include bullet hell and Gaster Blasters. His primary ability allows him to manipulate, edit, or destroy any object, living or dead, as long as he has a line of sight. He can also use a colossal hand called Warlock to slam enemies into the ground. By manipulating atoms, he can cause an opponent's body to instantaneously burst into flames; this technique is powerful enough to knock out even Abyss Sans in a single hit. With Blue Dragon, he slammed Malware into a place called Omega Planet, destroying countless surrounding universes. By applying Blue Mastery, he can freeze the space-time around an opponent. If used on a living human, this ability completely collapses their SOUL, causing instant death. There are others, but the list is too long... (Other) The King of AUs. He created King Multiverse Sans. He cannot defeat Faker404... As for others... well... I'm not sure if it counts as an awakening, but if he awakens, he can become Butterfly 404 or Perfect 404... it's just chaos...

(Appearance) His face and skin are black, and his eyes are red and blue. His mouth is yellow (not because he doesn't brush his teeth). His jacket-like clothing is black and red with a blue hood. The word "ERROR" is scattered all over his body. (Species) Skeleton (probably...?) (Role...?) A destroyer who destroys AUs. I believe he starts by killing Flowey and Frisk first... (Backstory) Geno Sans was trapped in a place called the Anti-Void and eventually glitched out. (Relationships) Error404 (William) Error404 is something of a master to Error Sans. Ink Sans His rival. (Physical Info?) Gender: Male Age: Around 20? Height: Around 116cm, same as the original Sans. Birthday: April 4th (Techniques/Abilities) Red Bones. Used for defense and offense. Some have sharp tips and can be wrapped in Blue Strings for attacks. (Blue Strings) Strings that emerge from Error's eyes. There are currently massive amounts of Blue Strings in the Anti-Void. He can manipulate the bodies of living creatures caught in these strings. (Error Blaster) Gaster Blasters with the same colors as Error. The lasers are white. They are surrounded by glitches. (AU Hopping) A form of teleportation. Allows movement within an AU. Using this ability causes a small amount of glitching. (AU Portal) The ability to generate a glitch in mid-air and pass through it to travel to other AUs. "It's not much different from AU Hopping..."

(Setting) I think it was something like Geno Sans lost to Error Sans, glitched out, and became Fatal Error... (By the way, Fatal Error is Geno Sans.)