Nicknames:

The Scarlet Lord
MalesGrow's Grandson
The Scarlet King's Son
Ten No Kami's Son
Pride's Commander
Scarlet-Eyed Heir

Date of Birth: Unknown

Place of Birth: TransVoid

Species: Leviathan/Polothorn
Gender: Male
Height: Unknown
Weight: 265,000 megatons
Eye Color: Scarlet

Just like the Chapter that involves Baldur, this character has a father that is from a different Multiverse that is not related to Undertale or it's AUs, but from another franchise wthat is canon and well known. The father is also the same.

Controlling Existence is not a toy for anyone to play with, not even me.-Heimdall

Heimdall is a hybrid child of a Polothorn and a Leviathan, and is an extremely powerful being in his own right, and one of the most powerful in existence. He is the child of Ten No Kami, the Daughter of MalesGrow, and The Scarlet King, a dark Old God from the SCPVerse, as well as the half brother of Baldur.

Backstory:

Born from the Being only known as MalesGrow, Ten was born from a husk of women who had passed away far before she was even a fetus and yet they were born anyway. Ten is one out of thousands of siblings, so many that numbers are all they can go by with only one having a true name. Malesgrow was a very neglectful father and was only ever focused on getting bigger and ascending up the Being chain of power, even to the extent of devouring his own children. Ten after seeing their father consume hundreds of their siblings Ten made their escape from the TransVoid, after making a deal with demon who had lost a fight with another Being Ten got their hands on the Book eyes allowing them to travel to a distant world where once they entered it found a large white void just looking for something to fill it. Ten then began to use their mind and intense powers to perhaps somehow make a better family. Ten then created a pile of pink smoke as her first creation, the pink smoke didn't do much at first, but then Ten gave it thought and it then began to question everything causing Ten to destroy their first creation. Ten then began to think hard on what they wanted to do and then they heard a chime in the void and found themselves staring at the original universe of this mysterious place, They found Undertale, they stared and watched it knowing better not to mess with the only thing there, Ten found themselves back in the white void before now with a new goal, making a new world.

However, at some point in the past, she discovered that there exists another Multiverse, that has immense power, as well as another realm that is able to exist alongside the TransVoid, but for the Multiverse that it has on its own. The realm was known as the Tree of Knowledge, and although she is unable to access it, she is able to see what it looks like. And needless to say, it is as large and as vast as the TransVoid itself, except that it is only having one single section, whereas the TransVoid has multiple section of the Being that has made it their own home to stay.

However, as she is looking at the Tree of Knowledge, she sensed that there is someone there with her, and is watching her. She turns around, and she saw that there is an entity that is watching her. She looked...unsure, and even looked very weary, as she saw the entity the appeared behind her.

Having appeared before her is an entity made of darkness. He has an anorexically thin humanoid body, standing much more taller than Ten No Kami, and emitting blinding red light. His skin resembled that of a burnt corpse, his hands were gnarled claws, and possessed two great antlers behind his head and multiple eyes on his face. His mouth is very scary, and describe it as a red whirlpool of swirling screaming faces, and even has faces all over his body, they are small, and look as though they are trying to escape. He is also possessing seven mouths which spoke profanities, 7 eyes all over his body that killed anyone who looked into them, clouded by smoke and fire, and poured endless blood and released an endless inhumane scream. Ten No Kami floats back, but being a very prideful being she is, she think she can take him on. And thus, she acts all high and mighty, thinking that she can take him down. But the entity calls Ten No Kami a mere child, and claiming that she is nothing more than someone that he can use for his own desires, and claimed the she is a mere demigod, while he is a True God, and identifies himself as the Scarlet King. Ten No Kami, however, believes that she can take him down, and thus, goes out to fight against him. But the Scarlet King has lived up to its title and fights against her, and simply uses most of his power against her, but does not use all of it, for he has plans for her that he knows that he can use.

Ten No Kami used all of her strength, but the Scarlet King fought back and did not lose ground, and thus, was able to win and pin her down. Ten No Kami struggled to get out, but she is weaker compared to the king. The Scarlet King than shows most of his true form to the daughter of MalesGrow, and she was so horrified at seeing even most of his true form that she cannot get the words out, and is even to stunned and scared to do anything about it. She has never felt fearful of her own life, until now, and this is the first time she has felt fear. And then, without wanting the Scarlet King let's put all of his power, and forced himself onto the Polothorn.

After he was done, Ten No Kami left the realm in which she observed the Tree of Knowledge, and she became traumatized as a result of what had became of herself. She has never felt so much fear in her life, and thus, she decides to not ever get close to the realm in which the Scarlet King resides in ever again. But she cannot think of what will become of her now, because now, she carries the Spawn of the Scarlet King within her, and thus, she needs to make sure that the spawn is eliminated as soon as it is born, and thus, makes sure to kill it. 

She waited for a very long time, for months for the child to grow. She waited patiently for the young spawn to be born so she can put an end to it. And when the child was finally born, and she gets to see it, although the child has Ten No Kami's features, the child also has features similar to that of the Scarlet King, and needless to say, feeling the need to slay the child, she tries to smash him to bits with her tentacles. But before she can, a glitchy portal was formed underneath the child, and was caught into a destroyer's hands.

The destroyer belongs to none other than Error himself, a Polothorn like Ten No Kami. Error is the forced destroyer and has been reborn, due to the tree of the Unnameable reforming his body and infusing him with his essence. When Error saw the child inside of his screen, he decided to take him and raise him as his own. Although he knows that the is of Ten No Kami, he also knows that the child has no choice in his life, and thus, decides to protect him from Ten No Kami. He then gave him the name of Heimdall, and makes sure that Ten No Kami does not find him. While unaware of the father's identity, due to not seeing it, he knows it is dangerous, and thus, make sure that the child is raised right.

Heimdall shows immense love for his adoptive father, just as much as Error cares and shows Heimdall how to live his life. However, he also knows that Heimdall needs to understand that there are hardships in his life, and thus, needs to be stern and clear on its hardships. And thus, when he feels like he is old enough, he raises shows him some of the bad sides, although not to the point of traumatizing him, and Heimdall even began to take some of the lessons that Error is giving him to heart. Error is also making sure that Ten No Kami, the Astral Mother, or even Ink does not find out a one the child that he has in his hands, and thus, makes sure to protect him with his life, until he is old enough. Despite this, he will show the good sides to balance the bad sides of existence, and does it equally. Growing up, Heimdall adores and cares deeply for his father, and Heimdall even began to create his own creations. But the creations weren't perfect and Heimdall wanted to destroy it, but Error stops him, saying that it cannot be perfect, because it has not been given the time to be so. It can be improved, but perfection is merely an illusion, and thus, is simply arrogant belief. This made Heimdall stop, and he took those words to heart, and leaves his creations be, and puts them someplace else. Although Ten No Kami does notice these creations and destroys them herself.

As Heimdall grew up, he began to manifest more and more of his powered, and thus, Error had to make sure that Heimdall does not get noticed by Ten No Kami, or anyone else. However, Error404 noticed, and questioned Error on the child, and Error was truthful, and explained why he hid it, and even sympathizes with the child, due to not choosing his parent, and was born only because of outside circumstances. Error404 understood, but demands him to not hide this again, as he also make sure to watch over the kid. And knowing that the child of Ten No Kami's son, he is able to know all of her powers, and thus, told Heimdall about the powers that she has inherited from Ten No Kami. Heimdall practiced with his powers, and is able to get a very great grasp on it and his powers are immense, already stronger than Error404 and ever the Astral Mother, and is stronger than even Error himself, and he himself is stronger than Error404, due to becoming a Polothorn. But as Error gave him an experience of being humble and being wise on what he says, Heimdall is very weary of his own power, and thus, makes careful use of it. But as he grew older, he began to know other things, that his own power us giving him. He began to know the past, the future, and is even aware of the other Multiverse, and it is making him panic. Thankfully Error and Error404 told him to gain control over his senses and they were both able to calm him down, so he does not wreck the Anti-Void with his powers, and his newfound nigh-all knowing knowledge allows Heimdall to know all of his abilities. Unfortunately, however, Ten No Kami noticed the child's presence and remembers it, and is able to find him inside of the Anti-Void, enraged to see that the child is still alive, and has now grown up into a powerful being in his own right. And thus, she tries to kill him. But first, she wants to make him suffer by making it look like that Error and Error404 will be killed by her hands. But Heimdall, caring and loving for his father, fights back against Ten No Kami, and does all that he can to fight back against her. And eventually, he was able to succeed, due to his power being far more superior and being much more stronger. But unfortunately, this act also caught the attention of the Scarlet King, and he knows that, and thus, is coming for Heimdall. Not wanting get caught, Heimdall decides to leave, but does say one last goodbye to his adoptive father, as he left the Anti-Void, and fled.

Heimdall did all that he can to avoid getting caught by the Scarlet King, as he refuses to become a pawn in his schemes, and he remembers all the good times that he had with Error, all the good times that Error had in teaching him, raising him, and make him realize how important existence is. And thus, he used his power to make a realm of his own, one that is in between the TransVoid, and the Tree of Knowledge, this, making him in between the realities of the Alphaverse/Underverse, and the SCPverse, where he will forge his own destiny, and refuses to become a pawn of the Scarlet King, and will take the lessons that Error had given to him to heart, and all for him.

Appearance:

As Heimdall is the son of Ten No Kami and the Scarlet King, he has inherited both of their appearances together. Like Ten No Kami, he is a pale humanoid, but with longer white hair that reaches down to his hips, and has large wide eyes, with a DNA marking going below from the left eye. However, unlike Ten No Kami, he is able to obtain his red eye, although the eye is now a much more Scarlet color, as well as the fact that he also has a second Scarlet Eye, giving him both eyes together. Like Ten No Kami, he also had tentacles, although the tentacles are much more larger and much more stronger than her. He is wearing an outfit that resembles a form of royalty, which is a black shirt with golden pads on the shoulders of a scarlet jacket.

With the traits that involve the Scarlet King, due to his huge size, he has fists that are massive and has gnarly claws, much more than even his father's hands, and just like his father, the skin on his own hands resembles that of a burned corpse, and he possessed two great antlers on top of his head similar to that of a stag. On top of his head and between the antlers is a type of crown-like ornament he made with his powers, and the crown has 7 spikes on top of his head. He has normal arms and fingers, has 7 rows of sharp teeth, although it is also possible that he has 10 rows of teeth inside of his mouth. He has also inherited the Scarlet King's tone of voice. It's described as similar to "the chittering of a billion infinitesimal insects", and swirling and constantly moving. His voice also was neither "high nor low nor cacophonous nor methodical", simply just being. Because of this, it makes it impossible to know how Heimdall is feeling, as well as the emotions he's expressing, despite the fact that he can express and feel similar to how humans can feel.

Personality:

Although Heimdall is a very scary-looking entity, he is actually not as evil as he appears. Although he has inherited the traits of both of his parents, the Prideful, Snobby, and Perfectionist nature of Ten No Kami, as well as the Cruel, Manipulative and Nihilism of the Scarlet King, with said Cruel nature also inherited from MalesGrow, due to being cared for by Error, Heimdall is able to push these feeling down and even suppress this side of him, as Error had shown him and taught him all that he knows and even the good side of existence. As a child, Heimdall has a very loyal and caring nature towards his own adoptive father. He is also a very loving child at the time. But as he got older, and he became nearly-all knowing, he became more colder and monotonous, but thanks to Error, maintained a little bit of his humanity and is able to act like normal people.

Although he is not a truly good person, Heimdall does his best to be a good person for the sake of his adoptive father, as well as for himself, because he puts existing for his adoptive father above the desire of the Scarlet King. And unlike Ten No Kami, he is humble to a degree and swallows his pride, but can still be a it prideful to those that are below him and are arrogant to him. And as he learns from Error, he does not let pride and arrogance blind him from Common Sense, and thus, keeps himself emotionless to prevent himself from being blind to the truth, and even relies on his Nigh-All Knowing Knowledge to help him with this horrible trait.

Powers/Abilities:

As the Son of Ten No Kami and the Scarlet King, Heimdall is an extremely powerful entity in his own right, more so than ever Baldur, his powers being nigh-absolute. As such, he is one of the strongest entities within the entirety of existence, being being able to currently surpass the Scarlet King, and being rivaled by Sol.

God's Will: With this Power, Heimdall can kill and or eradicate all life-related or similar to the AU it is connected or closely resembling to. This includes code similar to them and offspring and relatives included. This ability can also reach out to sister Aus as well. And has complete control of everything that resonates within where they roam and resonate.

Au Cinder. Cinder to Cinder, This ability can destroy all Aus that isn't grounded to what AU that it is similar to. This also means that all code fragments that have Alphatale code or code related to such code will be erased.

7 -Zen ishiki no: I can See You

The Gift: The Gift is a power that is given to beings that have experienced true suffering, have met an unfortunate demise or that just have a darkness in them unequal to any. When the gift is given it's usually given without true aware some even being able to live their entire lives never knowing about it. The gift is a white spot, it takes apart of the host body that is either empty or no longer has purpose and burrows there. from there the gift supplies them with intense durability, Ever-lasting life, and Void like code that enables them to never truly die unless a being of more strength than Ten kills them. The Gift tho great is a sign of control, Either it be willing or not Ten no Kami has control over being with said Gift.

Tentacles: Heimdall's Tentacles are large and are big enough to dwarf a gigantic mountain. Heimdall's tentacles can wipe out all code that they have made and any code related to it. The tentacles also make for great tools of destruction for any caught in their grip are immediately destroyed by the atom, and if not then are transformed into an Amalgamation of void and Alphatale code.

Abyssal Eye Beams: Heimdall has 2 Scarlet Eyes. Inherited from MalesGrow and empowered by the Scarlet King's own power, the Eye Beams are so strong that they can severely hurt even the Scarlet King himself and can even destroy the TransVoid or the Tree of Knowledge, although it will considerable effort to do so.

Consumption: Like MalesGrow, Heimdall can consume anything, such as concepts and Multiverses and even other Old Gods and Beings to make himself more stronger than before.

Eternal Transcendence: Heimdall has the power to be in an endless state of transcendence.

Matter Manipulation-Science Manipulation: Heimdall has the power to manipulate Matter and, ironically, Science together or separately. Heimdall, through this, is able to transform and revamp the composition of an object from solid, to liquid, to gas, change its size from microscopic to building-sized, or disfigure and reassemble an object's matter into another form, and is able to use this power to fill up the volume of the Multiverse, and is even able to manipulate planets with this power, as well as being able to destroy Matter. Through the ironic use of Science Manipulation, Heimdall is able to use science in order to accomplish extraordinary feats, such as warp the very nature and laws of the Multiverses, allowing them to affect anything in the Multiverse at any scale, from the biology of living things to the force of electromagnetism, to even the energies of the Multiverse itself.

Size Manipulation: Heimdall is able to change his size at will, being able to shrink or grow, although this does not seem to affect his powers in anyway, and can even shrink down to a size that is comparable to that of a human's. At his largest, he is much larger than even the Scarlet King himself.

Nigh-Omniscience: Heimdall is able to know almost anything and everything, even stuff in the past or future, despite the fact that he is not present in nether time period and is even aware of the SCPverse, despite the fact that he has not visited it. He even know all he can do, and knows much more than ever what the Scarlet King knows. Despite this, however, there are some gaps in his knowledge, and does not know everything, but does know more so compared to his father.

Foresight: In addition to his Nigh-Omniscience, he is able to see into the future and know what will happen, and mainly uses this when he is fighting against someone that is stronger than him. However, he needs to be directly focusing on the opponent, else he will be attacked.

Misery Empowerment: Heimdall has the power to feed on the suffering and negativity of other beings, such as Error404's suffering with his AU being destroyed, as well as his obsession of bringing it back, and feeds even on Error's pain of the torment that he had been through.

Abyssal Light: Heimdall can manipulate, generate, control, absorb and spread abyssal light - the combination of his two conflicting heriteges colliding into one mess of an element. Abyssal Light possesses the endless light energy and unimaginably large eldritch proportions of his genetic progenitors while also adding his own developed powers to it. It is an element that surpasses nearly all else, except for those that are above his power.

Scarlet Breath: Heimdall can breath out Scarlet Colored breath to corrupt the magic and existence of a person of AU/Multiverse.

Madness Inducement: If Heimdall desires to, by being on his presence, he can induce a dangerous form of madness to other people. He can drive them to the point of insanity and is able to deteriorate their mental health. However, he can also reverse the process, but only if he desires for it.

Reverse Effect: Heimdall is able to reverse the effects of an occurrence into forming the opposite results. For example, if something harmful happens to the user, such as getting punched in the face, the user receives positive effects from that outcome and feels pleasure and vigor as opposed to pain and damage.

Apocalyptic Force Manipulation: Heimdall is able to control an incredibly dangerous force, the one that causes all of existence to end. Apocalyptic force does not mean they need to necessarily destroy, just end a universal cycle making it the representation of end or omega. He can truly tamper with the end power of existence and terminate any universal cycle, creating absolute chaos.

Anti-Universe: Heimdall can create malformed versions of worlds on an Omniversal scale. Creating a second Omniverse filled with an infinite collection of blasphemous and chaotic realities. a verse formed of every fear and bad decision ever made or dreamt, a verse made up of every possible horror imaginable and grows more powerful with every evil action, bad thought or sin from the original multiverse and it's inhabitants. This verse literally feeds and thrives off "everything wrong".

Memory Manipulation: Heimdall is able to manipulate the memories of other people. For example, he is able to make a person forget how to use a firearm, even though they had practiced how to use it for a very long time.

Blood Manipulation: Heimdall is able to manipulate blood into however he wants it to be. He can make weapons out of blood, either from himself or from other people, or can use it in other ways, such as turning his own body into blood, just so he can appear elsewhere.

Primordial Darkness: Heimdall can manipulate the Darkness within the realm called the Darkness-Below, to preform horrifyingly powerful feats of immense might, such as making shadow tendrils and is able to travel through shadows.

Time N' Space Control: Heimdall can manipulate Time n Space around him, slowing down some things to a complete stand still or even being able to shatter whole parts of space itself. It is also able to mess with the concept of time within other realities, to where he can slow things down to a almost standstill like movement where characters believe their reaching him when in reality they couldn't be none the wiser.

Kin Connection: Like Baldur, Heimdall is able to feel a connection between his 2 Parents, Ten No Kami and the Scarlet King. He is also able to sense Baldur and Apollo, despite the fact that they are in their own separate realms. He is also able to feel the presence of the Scarlet King's Leviathan Children from the SCPverse, and MalesGrow's Children inside of the TransVoid.

Demonic Commanding: Heimdall has the power to unleash and control demonic entities from the Darkness Below, and even bring the entities out of the Darkness Below without needing the 7 Spears to make a portal for them.

Imperfect Omnipotence: As the son of the Scarlet King, Heimdall possessed immeasurable power and is nigh-unstoppable. He possesses unfathomable divine-eldritch powers that put him leagues above any of his siblings and even surpassing the Scarlet King  herself, who is even stronger than even Ten No Kami herself, and not even MalesGrow is able to match the power that Heimdall possesses. Only Sol or Mes has the power to rival this sort of might, and even then, victory could barley be achieve on Heimdall's end. Heimdall has the power to create organic or inorganic matter from nothing, either as finished objects or simply unfinished elements. He can create anything he can think of, whether conceptual or sentient. This includes the creation of energy, souls and life of any complexity, dimensions or realities, stars, just to make a few. He also can utterly destroy things. This could be anything and everything from small objects to entire galaxies or universes and possibly even abstract concepts and/or natural forces/laws. He even is able to create a pocket dimension that is between the TransVoid and the Tree of Knowledge, therefore connecting himself to the Alphaverse and the SCPVerse, and is unable to be found by the Scarlet King.

Relationships:

Ten No Kami: The mother of Heimdall, she hates him with all of her might and even fears him, due to what the Scarlet King had done to her, and thus, seeks to eliminate him by any means necessary. And when though Heimdall has grown stronger than even the Scarlet King, who is stronger than Ten No Kami, she still desires to find a way to destroy him.

MalesGrow: The Grandfather of Heimdall, MalesGrow fears him immensely, due to how strong he is, and thus, he does all that he can to make sure he does not get consumed by him. Heimdall cares less about him, focusing more on the Scarlet King's dangers.

The Scarlet King: The father of Heimdall and the child of Tree of Knowledge, he is cruel and diabolical, and is one of the most feared gods of all time. From the moment that he saw Ten No Kami, he sensed immense power close to himself, and it made it just enough for the Scarlet King to make a spawn in order to use him to end all of existence. And now, currently, the Scarlet King is trying to find him.

Righteous!Error (FGoD): The adoptive father of Heimdall, as well as the forced Destroyer and Polothorn, he is able to raise Heimdall and taught him all that he knows, as well as the good and evil sides of existence, as well as the importance of destruction and creation. In return, Heimdall loves his father very much and pretty much allows him inside of his realm.

Error404: Due to Error404's connection to Ten No Kami, Error404 was initially distrustful and keeps him under watch, so that he does not act like Ten No Kami, and even acts like an even more stern and strict parent in how to contort his powers, but after protecting both Error and Error404, he began to trust Heimdall much more than ever.

Baldur and Apollo: The Half-Siblings of Heimdall, Baldur and Apollo, while they have not met Heimdall, they are well aware of his existence, but stays as far as they could away from him, because they have their own stuff to do. Heimdall, in return, leaves them be and respects their privacy.

Atanti-ql-Paneu: A Spawn of the Scarlet King from the other Multiverse going by the title of SCP-682, he is a reptile-like creature that is able to adapt to anything and has an absolute hatred to all humans, he and Heimdall had met at some point in the past, and hold a sort of amiable relationship, even if Baldur does not side with him and cares little for his plan.

Quarseta-ql-Paneu: Another spawn of the Scarlet King, going by the title SCP-053, this one being a young girl that can make anyone have murderous intent in wanting to kill her. Heimdall, however, has the power to resist this effect, and thus, he is able to speak with her with no problem whatsoever, and thus, both her and Baldur have a very good sibling relationship with each other.

SCP-999: The entity simply known as SCP-999, is an orange gelatinous monster made of slime that can cause euphoria and happiness into other people just by touching it, and the one that is destined to change his father into a good person. Heimdall seems to only treat him as a pet, due to his nature and personality, but nonetheless, knows of the fact that he is his half-brother.

Notes:

Heimdall is stronger than the Scarlet King, being the only spawn capable of being able to surpass him.

The Astral Mother does not know of Heimdall's existence, and he prefers to leave that way.

Heimdall is well aware of Yaldabaoth and Mekhane, and is even stronger than the both of them.

Heimdall is well aware of the Anafabula, and is not daring to try his luck against her power.

Heimdall was able to see The Escapee, also know as SCP-3125, and he is fine, but does mention that the entity looked extremely bizarre.

Heimdall is well aware of his status as a fictional character, but he pays no attention to this sort of topic, and focuses more on his own stuff that exists inside of his realm.

The fact that I am able to utilize Science Manipulation is ironic, as the Scarlet King hates anything that is related to modern times, such as advanced technology and anything that is based from a future that is very advanced.