No CODE No SOUL
Introduced in chapter 7, J.404 is more of a demon then a transformation, coming out during 404's most weakest state of mind and darkest moment. J.404 is entirely different entity featuring his own personality separate from 404's and William's showing a more Sadistic and cruel like monster behavior dawning his catch phrase "No code, no soul" meaning he is just about unkillable. However his control over 404's body is only temporary since with William and 404 both fighting for control back J.404 only has a short period to be around ranging to possible 30 seconds to 3 whole hours.
J.404's powers turn 404's regular attacks into more extreme versions of his previous abilities, he's not above using his hands to fight either and without fear or a mind to break J.404 is very capable of going up against TransVoid like entities with little issue no doubt able to overpower quite a good number of them, since J.404 isn't a transformation and is just a different mindset this means he is also able to utilize 404's transformations aswell.
Error404 can no longer use this form, as Osiris has been split from him.
God Eyes
Working just like the God ray yet very much more dangerous, these beams shoot out of J.404's eyes and can track and follow J.404's targets anywhere so long as he can see them, once they hit the target both soul and the code of the individual are destroyed and erased completely.
Eyes of Belial
Gazing into 404's eyes for at least 5 seconds would send the most sane of people into a deep, deep fear that they could be paralysed by the very sight itself. It would even disturb the likes of Infected.
Mission
Error404's mission is to tear apart worlds and use the stray code to rebuild Alphatale from the ground up. He believes that the ends justify the means and that this is for the greater good. He believes that if Alphatale is reborn it will allow Aus to flourish and become better than what they are now, but thanks to his deal with Error sadly this will never be known for his deal was to help Error wipe out the rest of the Aus once Alphatale is finished.
After that's done, what hAppens between them from there is up in the air.
Henchmen
The Order is From the 1st/Best to the Last/Worse
Error404 has people he controls or they do his bidding because of his power.
These will be labeled from Controlled to Main
Controlled = Under Error404's 24hour Watch and never set free unless he says so.
Right Side = They have Free will, but they must do as he says and come to his side when he says so.
Main = These few Henchmen have their free will but still do what Error404 says just like with the right side Henchmen, but unlike them, the Main Henchmen are Error404's closest allies, so they can also help him make tough decisions and the main henchmen often can command the Right Side and The Controlled Henchmen to do their bidding.
There will be no adding to the list
Error!Sans - Main
Thought!Sans - Controlled
Cyan!Sans - Right Side
Syno!Sans - Controlled
Nightmare - Right Side
Killer - Controlled
Sightings/Rumors
Geno says he once saw a weird-looking skeleton walking around, but when he went to talk to it, it fled into the darkness.
Even though it can't talk, the Sanstrosity has seen Error404 but didn't interact with him for fear that he may be attacked.
Ink!Sans has claimed and told Error!Sans that he saw a figure similar to him, but Error didn't listen and blew it off like Ink was trying to trick him.
Undertale Frisk once told Sans that they saw another him wandering around the woods and fields of Snowdin and Waterfall.
Rescuetale Gaster was taking pictures of wildlife when a white thing that resembled Sans came into view. Gaster was able to take a picture of the being before he vanished.
S.T being the Judge seeks to eliminate him but he has only seen him once.
What!Sans and Tahw!Sans has seen him, during a fight they were having.
Hero Sans Thought He Saw A Suspicious, White Sans Walking around and gazing at him while he Was Fighting Dark!Sans
Metroidtale Undyne barely caught a glimpse of Error 404 and tried to attack him with a swiftness type of super, homing missile, but Error 404 escaped before the missile could get to him.
Negative!Sans told his brother once while he's exploring Horrortale, he found another him, but white. He didn't interact with him because he has a fear that it might attack him. He only sees him once.
Floweytale Flowey has once claimed to have seen a strange, glitchy Sans once, he tried to take its SOUL but he found the vine he used to do so ripped out from his stem, after that he fled back to his AU.
Inkmare once saw a Sans going around and assumed it was Error in cosplay, so he left it alone.
beta!Toriel once confused him for Crimson. The results weren't pretty.
Echo Flowey saw him wandering around the Neutral Timeline once, but he disAppeared before he had time to tell anybody.
Killer saw some strange white sans while wandering around in Horrortale but when he tried to attack, it disAppeared.
VDash!Gadget at one point had to escape a collapsing Null Space Void which was caused by the Appearance of a "White big-boned looking Error Skeleton with a white and blue hooded robe, black shirt and shorts, and blue shoes."
Error404 once freaked Abyss out by manipulating the code of the Abyss.
One day, as an Asgore was watering his flowers, he'd seen two glitchy skeletons discussing topics by his flower garden, and before he could even welcome them to drink tea, they'd already left.
Trivia
Error404 is a very rare Character to see, due to him being an absolute recluse. Then again, nobody probably wants to see the guy.
Error404 now has a SOUL, being a HOPE (white) SOUL with various INTEGRITY (blue) stripes over them. This gives him a set HP and DEF.
Error404 likes to watch and collect Ink!Sans's drawings, which is why Ink makes so many because whenever he makes a new drawing it magically disAppears.
If Error were to for any reason touch Error404 while they were not in a calm state, they would end up bugging out the entire Multiverse.
Error404 is the strongest member of the Error family.
Error404 is so strong that he can make another Error!Sans if he so wishes to at the cost of his code.
Error404 is the biological brother of Alpha!Sans.
Error404, in a way, is the technical father of Error!Sans.
Error404 loves to eat cookies.
Error404 alone can beat all the deities with little to no difficulty and he could probably take on half of the multiverse, though he prefers to only fight directly when necessary.
Error404, being the self-proclaimed 'God of The Multiverse', is the strongest Sans in the multiverse.
Error404 has a stupendously high DEF, yet has moderate HP. If a LV 19 Frisk was to slash him, it'd deal 0.7 damage.
Error404 is the only Sans strong enough to control and make Error and any other Powerful Sans his puppet with his Mind Manipulation, Examples: Ultra!Sans, Omega Sans, Ink!Sans, etc.
Error404 isn't aware that his brother Alpha!Sans is alive, blinded by his own grief to the point he is ignorant of it.
Error404 and Error have a very specialsecret.
Error404 isn't bad entirely. Despite his cruel actions, in his mind he considers it justified, only doing it to bring his loved ones back, considering it his duty.
Error404 hates pranks because they're childish and a waste of time to him.
Error404's birthday is on the 20th of December.
Error404 can take away an entire world and bring it into his realm. For example, imagine Jupiter where the moon is......Yea that's how big his realm is.
Error404's Realm is a giant cliff side that leads into the very core of the Multiverse and has an endless ceiling covered with scenes of AU's, visions of those he has control over, and drawings that Ink had made.
Error404's mother is known as The Astral Mother.
Error404 is an extremely dangerous entity to come upon, and the only way to possibly win a battle against him would be to simply flee. There's no point trying to kill what can always return.
404's streaks of black lines on his face are scar marks that he'd made from his breakdown in the Anti-Void. The said marks were once so deep, they were able to have a whole finger stuck in them, yet they soon repaired to as much as they could by time.
Error404 Sans can collapse the Null Space void simply by stepping foot on its realm.
Error!404 was created by SHADIKAL15.
His theme is made by Jinify - AKA AbyssSans199.