Meh, Cosmology is more correct. I don't see any myths, legends or stories in sight.
Alright, my proper update for Kurix's past:
Kurix
Title: The Lupine Chaos Brawler
Attribute: Strength
Number: II
Appearance:
Kurix stands tall at 6' 4", and is broad-shouldered and very well-muscled, yet his body isn't out of proportion, and none of his muscles bulging out of skin compared to how strong he truly is. He has green/grey eyes, and pure silver, spiky, neck-length hair. The style is similar to Axel's, but the spikes are shorter and more numerous. He also has a small, clean cut goatee on his chin.
Past:
Kurix's first came into 'existence' some three or so years before Organization XV was founded between Xemnas and himself. Because of unknown circumstances, except for an unusual birth, Kurix is born lacking the memories of his time in his former life, as Riku.
Kurix's first moments and months of life are in the world depicted in the Manga and Anime series Claymore, a world inhabited by not only humans, but beasts known as Yoma, and hybrids of the two, known as Claymores for the huge swords they wield to vanquish the Yoma. Kurix is soon found by the priest of a local town, who takes Kurix under his wing and, over the course of several months, teaches him a huge variety of things, for Kurix is also hungry to learn, to the point where his intelligence is on par to what it was before Riku's death. Around this point, the priest names him Naullus, a rough twist on the Latin word meaning Nothing, both suitable to Kurix as a Nobody and what was in his mind at birth.
During his learning process, he becomes fascinated with the Claymore, to the point where he wants to become one, but, strangely, there are only female Claymore, and only women are accepted to become them. Nevertheless, Kurix dream to at least see one comes true some weeks later, where a Claymore deserter on-the-run dispatches a Yoma that was attacking Kurix and the townsfolk as they were leaving a church service. As the Claymore runs away, Kurix follows her, and eventually, learning the truth of the Claymore and the Yoma, offers to shelter the Claymore, her name Miria, in his own house for as long as he can. The Claymore accepts and, while still in hiding, the Claymore teaches Kurix deadly swordfighting techniques, and the two even fall in love, to the point where Miria becomes pregnant. Although neither of them are truly human, that simple fact is perhaps the only thing that allowed a successful pregnancy.
With the hormones flowing through her body, Miria loses her ability to surpress her Claymore energies, and soon another hunting team of Claymores is dispatched to find her. One Claymore, a male, strangely, moves away from the group one night and find Miria, ultimately decapitating her, and even cutting open her womb and pulling the unborn baby out, him never having seen a pregnant woman before. Enraged beyond belief, Kurix fights the Claymore in a battle the Kurix, in the end, seems to win, but leaves the village in ashes, most of its inhabitants dead or fled.
Despising the memories of what he has lost so much, Kurix's mind wipes itself clean of all personal experience, leaving behind knowledge and facts and figures, and through sheer force of will, actually half moving into Non-Existence to assist transit, Kurix relocates himself to another world, this time, Amestris, the world featured in the Full Metal Alchemist anime and manga series.
Awakening in a desert, Kurix is warily accepted into a race known as the Ishbalans, more defined for the God they worship than their physical features. With skin tanned by the desert sun and silver hair, yet lackin red eyes, Kurix is warily accepted into the Ishbalans. Learning of their ways of life and their religion, as well as those considered heathens by Ishbal, taking what God has made and turning it into something different, Alchemists.
Alchemists use arrays known as transmutation circles arranged in specific patterns to take matter and make it into something different. Alchemy works in three stages, and one strict law. The first step is to understand the shape of matter, the second to break it down, and the third to rebuild it into something different. The law is known as The Law of Equivalent Exchange, and dictates that in alchemy, and nearly everything in life, that your output must equal your input, thus, you cannot make a ton of gold from a glass of air, and that is why people work hard at anything they do, in the hopes that they recieve something in accordance with their effort.
When the Ishbalans find out about Kurix's facination in the forbidden art of Alchemy, he is quickly exiled from the Ishbalans. Kurix then attempts to become an Alchemist, and shows a particular flare for the science, yet the State Alchemists are wary of him, formerly being an Ishbalan. Eventually, learning a strange technique where Kurix needs only to clap his hands to perform Alchemy, this putting him ahead of a great deal of Alchemists, and his tendency to not follow the rules, Kurix is yet again removed from a group he attempts to fit into.
One last attempt to fit in somewhere in Amestris finds Kurix among the Homonculus, human-like creatures composed of a Heart and Body, but lacking a Soul, and are produced whenever an attempt at Human Transmutation fails. Although not recognising his own incompleteness, Kurix tried desparately to fit in, and is branded with the Mark of The Orobos, a serpent eating its own tail, on the back of his neck. Only too soon is it burn away, leaving an ugly scar, and Kurix removed once again from the group. Using the same method of how he came to Amestris, Kurix finds himself in Shibuya.
Finding himself able to fit into a much easier life as a retail shop owner, Kurix goes by the name of Tsubasa, and is quickly fascinated by the Reaper's Game, a life-or-death race around Shibuya that pits Players and Reapers against each other. Occasionally, Players are able to take a break from the action at certain shops around Shibuya, Kurix's shop being one of them. When in the shop, Kurix regularly heard the Players talking about the Game itself, only furthering Kurix's fascination. A car accident later, and Kurix finds himself in the Reaper's Game, partnered with Neku, a veteran Player.
The two survive the week of the Reaper's Game, and at the very end, Kurix, finding that only on Player may be restored to life, and with a strangely intense urge to live despite now knowing what for, Kurix kills Neku, wins the Game, and, again not wanting to hang around in a world, flees. For a month or so, Kurix is alone in the Darkness of the Dark Corridors, until found by Xemnas. Xemnas, recognising Kurix from Riku, tells Kurix is real name, and the memories of his former life flood back to him, as well as those he forgot in the Claymore world. The two then found Organization XV, where they will find other Nobodies like themselves and help restore them to completion. Soon after, the third member, Cyolx, is found, and joins.