Undertale OC Wiki


* The author of this article is hard at work writing this article, please don't make it any worse.

* Be good, alright?

This article is still being worked on. You can help the Undertale OC Wiki by expanding it.

"Regret, you don't have to be Error!sans, your not an murder, but you still have a job...just like me. We are in control of how this multiverse runs now. Don't ponder over something you have the power to change."
– Radiant

Radiant!Sans is a Sans variant similar to a Swap!Sans. Radiant was created in the far future to become the new Protector because the unbalanced multiverse was destroyed and corrupted. Ink was unsuitable for the job and unpredictable in general. Radiant was specifically created to protect and defend everything, and he travels the multiverse in hopes of restoring the balance. He wants to follow in the path of Ink!Sans, of whom he looks up to. He has no intentions of creating universes but will follow the orders of the creators when an AU needs to be brought into existence. (This is very rare, seeing as the multiverse perpetually fuels itself). His only motivation is to protect and guard all Monsters. He was taught later that he needs to protect Humans as well, and that is part of his job description.


Radiant Sans was created in a lab in the AU RadiantTale (WIP). He was designed to protect monsters from humans, in defense against any possible genocide routes. He was also made to protect them on the surface (once they broke the barrier). He was treated like a "guard dog", which he did not mind, as Radiant could not think for himself at the time and wasn't aware of the insult.

He was sent to a rabbit's family to protect them. Radiant became part of this family, learning many different languages and gaining much knowledge. They were surprised how well he could understand them and how quickly he learned. They named him Sans. (This was not supposed to happen. Radiant wasn't intended to learn anything beyond his commands). Radiant was content with his life and loved to play with the other children in the family. Despite this, he never saw himself as anything more than an animal.

His world eventually had genocide route run on it and he failed to prevent it, resulting in his foster-families' demise. He decided to move on and find something else to protect. He eventually came upon a glitchy portal, and, not knowing any better, fell through it. This led him to the Anti-void, where Error!404 Sans was residing. Error!404 taught him how to be self-aware, how to travel through the multiverse and how to code reality. He then then kicked Radiant!Sans out of the Anti-Void in hopes that Radiant wouldn't become corrupted or turn into an Error. Radiant still likes to visit him (and uses various, somewhat lame excuses to do so). He now travels the multiverse and finds others to defend.



Radiant has yellow sun-shaped eyes and a long, boned tail with a black furry tip. He has purple markings across his eyes that leads to his arms, chest and legs. The markings are wrapped around him like bandages but are there to keep Radiant's power stable so he won't fall apart from using too much magic. He has sharp teeth and fangs connected to his skull, intended to give him the ability to bite and attack when the situation called for it. He has two purple tongues, which was an error in his design. Originally, he was only supposed to have one.

Radiant wears a black baldric around his left shoulder and right waist that carries his bone sword. His sword's grip is wrapped with thick bandages and has a sharp pointed end made out of Radiant's magic. He wears black long-sleeved gloves and a sand-colored scarf (The scarf was his first creation). He wears black snow-geared goggles because he thinks they look cool on him. The goggles can be seen hanging around his neck or on his forehead. He sometimes uses them to look at the sun or something bright. He has a little black pouch wrapped around his waist that usually carries objects Radiant finds interesting, (like little rocks, feathers, leaves, etc.), or just random things in general. Radiant wears a short cyan, grey and navy blue jacket with black straps around the sleeves and black-striped turtle-neck. His jacket matches his shorts. As shoes he wears long black socks (similar to soccer socks) and long cyan, grey and navy buckled boots, much like military boots.


Radiant is happy go-lucky, child-like in nature, though he can be blunt and is somewhat strange. He tries his best to be an optimist, and all he wants to do is to protect others. He is playful and kind, and he likes to interact with other AU's denizens. He adventures and and loves to travel. He is usually content and smiles through any kind of pain, trying to make everyone else feel better. When confronted with other beings who are depressed, he will do his absolute best to cheer them up.

When Radiant is told certain commands he will follow them. If he is told to kill, he will kill. He still has his obedient weakness, and is never aware of what he has done due to that weakness until later informed. If told to do so by the creators, he will do just about anything. Radiant never tells anybody about this because he doesn't want to be taken advantage of, but now that he is more aware of himself and his feelings, its easier to ignore these trigger commands. The only monsters that knows about this is Error!404 and Regret!Sans (WIP).

Emotional Tells:

His tail wags when he is euphoric and his eyes become larger.

His tail droops or goes between his legs when he is guilty, scared, or saddened and his eyes become smaller.

His tail does nothing and he will have normally shaped pupils when he is forgetting something important.


  • High Tier Regeneration: He can reform though his dust/code, even when his soul has been ripped apart.
  • Bone Magic: His bone magic is very similar to that of Undertale Sans's, just with higher damage levels.
  • Radiant GasterBeast: He can summon the full-body form of Gaster Blasters.
  • Teleportation: He can teleport anywhere.
  • Code Manipulation: He able to turn someone or something into a completely different thing, or control a victim.
  • Unlimited Creation: He can create anything, including his own AUs and timelines. (If he wants to make a dog with a duck head he could do it. There are no guarantees on its survival, however).
  • Speed: Maximum speed is around 45 mph.
  • Endurance: Radiant can fight for up to a few days straight before passing out from exhaustion.
  • Flexibility: Extreme flexibility.
  • Strength: Radiant can lift up to eight times his body weight.


Error!Sans (Frenemies)

Error met Radiant during Radiant's exploration through the anti-void. Radiant!Sans was about to set up a portal to leave when suddenly his soul was tied up by blue strings and he was brought to Error. Error!Sans's mental stability at this point was questionable, having lost his purpose when the multiverse was destroyed. He had been stripped of his destructive powers and been forced to sit in the anti-void for decades. Radiant!Sans had made a cheery comparison between him and Error!404, grinning the entire time. This reminded Error!Sans of Ink, his old rival. Error!Sans immediately killed Radiant!Sans. Radiant's body was reformed in a few days and he hurriedly left Error, not wanting to die again. Radiant occasionally visits Error and attempts to cheer him up.

Ink!Sans (Enemies)

Radiant met Ink at Radiant's first AU creation. The former guardian was staring at the the sky, eyes white with his vials broken and empty. Radiant, curious of who it was, walked up to Ink with a newly created pink and purple glowing flower. Radiant greeted Ink, only get a curt, monotonous response. Ink!Sans asked "who are you?", to which Radiant!Sans replied, "The Protector of AUs!" This caused Ink to snap, out of fear of being forgotten and rage. Ink!Sans attempted to kill Radiant, but Radiant!Sans escaped before Ink could do so. Radiant doesn't see Ink as a bad person, feeling sympathy and guilt for his predecessor, but keeps his distance.

Dream ("Babysitter", Friend, Assistant)

Radiant met Dream while exploring the Multiverse with PaperJam. Radiant sees Dream as a kind of grandfather, and likes to hear stories about the past and how were things like before. Sometimes Dream plays with Radiant or keeps him company whenever Radiant!Sans is bored.

Nightmare (Acquaintance)

It is Nightmare!Sans's opinion that Radiant's only purpose in life is to annoy him and eat food.

PaperJam (Guardian, Guide)

PaperJam found Radiant after he was booted out of Error!404's anti-void and accidently brought into a corrupted AU. if it wasn't for PaperJam, of whom got him out of the AU, Radiant!Sans would have been ripped apart and sent to a far corner of the anti-void for a sizeable amount of time. PaperJam soon discovers that Radiant!Sans is to be the new protector of the multiverse and, having experience with his life with Ink, helps Radiant learn what he needs to know about the creators and the Multiverse.

Error!404 (Teacher, Friend)

Radiant met Error!404 at the beginning of his journey. Error404 killed Radiant in their first encounter, though Radiant!Sans wasn't scared, as he didn't understand death at the time. Radiant decided to declare Error!404 as his new master. He waited for days to receive any kind of orders. Error404 thought about using Radiant as a tool but decided against it. He tried talking to Radiant a couple of times but never got an answer, only a couple of expressions. One day Radiant copied one of Error404's sentences to the smallest detail. This made 404 decide to tutor Radiant!Sans and, in a few months, Radiant knew how to speak, walk and manipulate code. Error404 saw Radiant glitch once and kicked him out of the anti-void so Radiant's code wouldn't become damaged as his own. Though Radiant!Sans still tries to visit the "glitchy old man" quite often.

Regret!Sans (Rival/Brother-Figure/Friend)

Radiant saved Regret from death via corrupted code. Radiant dragged him out of a part of the anti-void which was Regret's former AU (Destroyed by V!RU5). Radiant brought Regret!Sans to Error!404, who helped restored his code and recover his health. Regret was quiet, scared and stubborn at first. Radiant helped him calm down and taught him all about the multiverse and the AUs. They later became friends/brothers.

Infected (Enemies)

Radiant does not like Infected because of his motivations to corrupt and destroy and was angered when he heard what he had done to Error404. They never have never met, and Infected never plans to meet him, but to Radiant, Infected is a kill on sight.

V!RU5 (Enemies) (Information coming later)

Radiant meets V!RU5 through Regret, and seeks to trap the virus who tries to take advantage of the broken multiverse and take over.



  • Likes to dance
  • Shares cotton candy with 404 sometimes.
  • Regret feathers is his favorite pillow/bed
  • Bothering Nightmare is top priority
  • Can create AU's, (Has to know every detail about the au to recreate it)
  • Radiant was created on Feb 30th (First time being shown to public)
  • He likes music, and singer (he is a terrible singer)
  • Fear of cats
  • Memory is a little bad
  • Part of him was made from a gaster-blaster (skeleton dragon or somethin)