Kotoblade is the ultimate outcome of what an omniversal traveler (not to be confused with the original Omniversal Traveler, though this story does indeed relate to the original traveler in the paragraph below) named Satoru became after he was banished (not erased) from existence by The Supergod Council. He then resonated in the Kalyubi Dimension for an indefinitely gigantic period of time before deciding he wanted freedom and began conspiring with mortals among the Omniverses.
Satoru was a friendly, kind-hearted mortal human with high combat skills, who grew very powerful among decades to come. One day, he joined a very large -verse traveling program, where thousands of others had joined in hopes of discovering new life beyond the multiverse, which had already been pretty much fully explored (Satoru came from a timeline in the far future), as their primary intention was bringing back the original Omniversal Traveler from The Outside, but little did they know, the traveler went Beyond.
Satoru was eventually picked, after his training which spanned a few years, to go on a special mission by passing through the Archverse chain, to travel outside the omniverse. Satoru was obviously excited, so he had prepared, and even got to know his nine other crewmates during his preparation time, who were about, if not, just as excited as he was to exit the omniverse. They all boarded a massive starship-looking spacecraft which resembled a dagger, but the commander of the traveling project explained that the point at the end of the dagger was actually a superweapon made to destroy powerful cosmic entities who attempted to take them out, or large structures, so they wouldn't be destroyed mid-mission, hence the dagger-like spacecraft ship. This spacecraft was called the Omnius-Infinity. This ship also had other methods of defense, but they all paled in comparison to the cannon at the front.
After a few months of travel at speeds made by a device that was designed to pull the spacecraft away from and into certain dimensions and frequencies to jump infinite distances, Satoru and his crew had just passed the bubble of the Omniverse, and saw the Godverse pair, with Creator and Destroyer resonating in them. However, the two supreme beings didn't really care, since they knew that travelers had commonly been exiting the omniverse, and that they even invited the freedom of explorers among the Monocosm. After traveling through the outside for a great while, they discovered the mostly unknown extra-omniversal space known as Beyond.
The entire crew was immediately mystified at the peculiarity of Beyond and went out to explore, where they eventually discovered the same dimension that the omniversal traveler resided in when he exited the Monocosm and entered Beyond. They found this dimension with a device that detected alternate planes of existence, but, since they were in The Outside, it was easy to detect this dimension, since it was like spotting a smaller Universe. The small pocket dimension was drastically improved technologically after the crew decided to create a checkpoint for themselves, starting where the traveler left off.
The crew attempted to enter Transcendentem, which they did momentarily, but in a blinding flash of light, they were warped into the realm of The Supergod Council, where they were confronted by Conceptilum, Paradoxus, Imaginatim, Realitus, Logixel, and Unthil, who were interested to know why Satoru and his crew would dare attempt exiting Beyond, and then had a court-like debate on whether or not Satoru's crew should be punished or not for attempting to travel beyond their reach. In the end, the supergod council verbally wiggled their way around the weak reasoning of the crew, who then merged into Hellensoerensen. In an instant, there was a white blast of light, which lead to Satoru's partners being erased from existence, due to their deep-seated evil intentions after they exited the omniverse, such as taking energy from the supreme beings of that Monocosm (creator and destroyer) unbeknownst to Satoru. Satoru, however, was only banished from existence for associating with them, but with a completely clean set of intentions. He was unable to ever return under normal means, but was still thankful he didn't have the same fate as the 9 other members of his crew.
Satoru woke up, quite startled but also a bit tired, to a light blue hue in a seemingly desolate void, floating downward towards a blank abyss seething with dormant energy, which felt strange to him. It was then that Satoru realized that he entered the realm of those who are banished from existence, somewhere where only the gods could send things, The Kalyubi Dimension. Satoru, after a large period of time, met other banished entities, and after another large period of time learned to use a form of magic, named Koto. Satoru then nicknamed himself Kotoblade, since he became a manipulator of the magic known as Koto, and the fact that his crew's old ship was shaped like a dagger.
Kotoblade, in his early stages of entering the Kalyubi Dimension, was put through extremely long periods of torture by stronger entities in the dimension until he could break out of the long periods of pain, or if the bully-like entities simply got bored, but this urged Kotoblade to keep developing his usage of the Koto magic, and his power alone, eventually developing a new branch of abilities from rigorous training throughout the millions of eons of his time in this dimension. He even developed his own set of abilities with a forbidden, but exploited form of regeneration and matter manipulation called Demon Thread. It was at this point when Kotoblade was no longer a being to be toyed with.
Kotoblade proceeded to exact revenge on those who toyed with him by repeating the same torture methods tenfold, and, eventually, Kotoblade made a name for himself throughout the Kalyubi Dimension. Kotoblade even had a group of people who followed him, some of which were once on his bad side and wished to not face his wrath.
The seemingly eternal (from a mortal's perspective) period of time and the purely insane and grotesque imagery Kotoblade witnessed, experienced, and caused, completely destroyed his innocence from when he still had a clean personality and turned him into an absolutely remorseless sociopath. Kotoblade would then reign throughout the Kalyubi Dimension by destroying all who opposed him, and even killing the innocent from time to time simply because he grew bored of the lack of action around "his dimension." Powerful enemies would be toyed with for a while before being deleted by Kotoblade, some even stood a chance, but this causes Kotoblade to become aggravated easily and erase them on the spot. Entities that bullied young Kotoblade in the past would be put through eternal torture.
Kotoblade even took the corpses (or living bodies) of his mortal enemies and turned them into Kalyubi Glass, which he wore on a necklace around his neck. Many leaders that conspired with Kotoblade wanted to free him from his dimension simply to steal his necklace, which Kotoblade is likely aware of, but simply doesn't care, as his intentions far outweigh the intentions of those simply wanting more for themselves and less for others.
Kotoblade then mastered his usage of the Koto magic, and began making unbreakable deals with other kalyubi demons that wished to work alongside, or under him. Kotoblade also used this deal-binding magic form to make deals with mortals. (However, kotoblade could not escape the kalyubi dimension without weakening the Supergods who had the Kalyubi dimension bound in a lock so nobody could exit it, so Kotoblade found out how to stop time to create small rifts and talk to mortals in these time-stops.) The deals would involve giving mortals what they wanted, sometimes willingly or unwillingly possessing them only after a deal has been made in exchange for their loyalty in Kotoblade's plan to escape his dimension and destroy the supergods, so he can finally exit his beyond bubble and enter Transcendentem like he had originally planned. Despite Kotoblade's irredeemable qualities, he still retains the same passions he had while he was Satoru, specifically, those of engineering and exploration.
Satoru was a young man with a pale skin complexion, and his hair turned blue due to him experimenting with a homemade cancer cure. He usually wore black clothes with brown hover-boots that had a similar appearance to that of work boots. (in our era)
Kotoblade's hair is all burnt off due to trillions of battles over the eons. His skin is also bleached a light green due to his exposure to several different magnitudes and types of Koto magic. He wears a cloak with baggy sleeves, especially around his wrists, and a large zipper down the middle. He wears plain black shoes, resembling that of an elves. He also wears accessories from time to time, more notably, his necklace.