Name: Castiel Emyia

Age: 17 years old

Race: Half Angel half human

Hair: Golden

Skin: he has very tan skin, which is surprisingly smooth to the point it looks at the same time healthy and delicate
Eyes: the left one is pitch black and capable of seeing all sins of a person; the right one was lost previously and now it was replaced by a Divine Eye of a light-related deity and it allows him to control all light energy in his line of sight as well as absurdly high reaction speed, almostin the level of the sharingan, the eye is a celestial blue by the way.

Other dinstinctive features:
-he lost his right arm and replaced it with Argetlain, a weapon created by using the energy of the world, designs of a weapon made by Merlin, and fragments of Excalibur that were drenched in king Arthur's flesh and blood.
-He has currently 8 wings, the ones in the left are pitch black like the moonless sky while the ones in the right are golden and feel holy and sacred.

Weapons:
-Kupriotes – a simple sword, it is based in Alexander's sword and it only gives a slight increase to Castiel's natural charisma and lightning resistance. But it is the blade he is the most familiar with so if it comes to pure swordplay he would use this one the best.

-Hruting – a huge black sword. It look impractical at first glance but it has two skills that more than make up for the excessive bulk of it, the first being that once it 'tasted' the blood of someone it won't stop its attacks towards it, making it a weapon that tracks other while also making the most optimal attack at all times. Feints are useless against it. Another ability is that the more blood it is drenched in the stronger a curse in the blade becomes, a curse that makes the user insane but also raises his physical attributes further. Castiel's weapon also carries within it the soul of a World-Devouring Wolf, a divine beast that can devour entire worlds in one bite and is never satisfied.

-Clarent – the weapon that is most dazzling than any silver, it is a weapon that can only be used by someone who is recognized as deserving to be king. It has the ability to amplify the user's every parameter and also has the ability to amplify attacks using it to create thunder strikes or giant energy attacks. It was created to have a pseudo-will and is very competitive;

-Gandiva – A bow based in Arjuna's own bow. It is a divine weapon that is made of pure divine flames given shape and hundreds of rare materials, in the matter of bows it is hard to find any that could even come close to match its power. Of course its excessive power also comes with corresponding consumption of energy making it impractical for Castiel as he is now to use it. As long as you pull it an arrow appear, it is made of the user's own energy amplified by the weapon, it is possible for the user to put more power or try to put specific powers into it but if the energy goes beyond a certain threshold the arrow becomes of fire so using things like water or ice to make an arrow using Gandiva is counterproductive.

Argetlan – a prosthetic arm made by using the fragments of Excalibur, energy of the world, flesh and blood of king Arthur, blueprints based in Merlin's original designs but amplified by the work of Galiei, due to a trick used by Galilei it also has managed to get a part of Kokabiel's powers as the Star of God, granting it higher light power than the original as well as some amount of fire as well. It can release and control the purest form of light energy and the amount of power it contains is no joke.

Left Arm Spirit Bone – World-Devouring Wolf bone – It is a 700.000 years spirit bone that has the ability Devour, it grants the ability to devour any type of energy touching Castiel's left hand and turn it into pure energy for Castiel to use. There is no type of energy that can't be used by this and even attacks can become useless when hitting his left hand.

Skull Spirit Bone – Spiritual King Baize bone – it is a 200.000 years spirit bone and carries two skills. The first is complete immunity to any and all mental attacks, ilusions and any other type of thing that damages his soul are all impossible to affect him, excluding if it is something self-used like the curse of Hruting, but it still dampen its effects greatly. The second is Complete Understanding, an ability that allows him to learn everything another has been through as if it was himself who went through it, but he can only learn it while sleeping. One thing of interest is that he can select exactly what he wants to know and no matter how strong the other may be none can escape this overbearing skill, especially since he can launch it without others ever realizing he did as it is so secretive that even noticing it is neigh impossible.

Left Leg Spirit bone – Purity Dragon King's leg – it makes Castiel completely immune to any and all poison or dangerous substance, making assassinating him much harder and be able to survive some of the bio-hazard experiments that some of his girlfriends tried to pass up as cooking (but he would never call that true cooking, just a murder attempt). The second skill is called Purity Halo, it is an area of effect skill that eliminates any poison or substance he considers a taint in a large area, the bigger the area the more energy he must use but with it no poison can work against him or those close to him.

Angelic Foundation Armor – an armor that is only usable for angels in the level of Super-class (the equivalent to continental class DPUs in OEG), Archangels, or those destined to be Archangels, like Castiel. It is an armor capable of accumulating twice the amunt of energy the user has, grants an increase in strength, defense, magic resistance, light energy manipulation, and lessens the needed energy to launch an attack. It is truly an armor that becomes monstruously strong when used by those who are truly strong, much like the Archangels. Using one, an Archangel can fight even those in higher level or multiple enemies at once without a informations:
Castiel's body is an oddity. He has three distinctive features that make measuring his true potential near impossible. His first one being that he is part angel, to be more specific he was chosen by birth by Heaven's System to receive the name of Castiel, the archangel that was the Shield of God and the being with the strongest defense in the entire universe he came from, while Castiel also is son of Gabriel, the Strength of God and being her son he should have potential to have near unlimited strength. Only based on that he would definetly reach mid Leader-Class at the absolute least. An Archangel is capable of using the power of his 'name', as such when Castiel uses his the wings in his back becomes completely impossible to breach, not even those much stronger could and even those in the absurd level of strength would not find it easy, and that is because he is currently weak in comparison to what he can reach.

Background

The thing is that he is also half human, a being that has true unlimited potential for growth, and considering that he is the son of Shirou Emyia, someone who was considered one of the strongest humans in the entire universe it made Castiel's potential even harder to define.

But the last part is what is troubling the most, he also was born with a fragment of the corrupted Holly Grail, carrying with it both a connection to the throne of heroes, making him possibly able to learn and copy Heroic Spirits much like a demi-servant, but also having a part of Angra Mainyuu, a god that represents and carries All Evils in the World. That makes it so that Castiel's potential for Evil and Cursed magic be just as strong or possibly even more so than his potential for holy and light elements.

This combination that should have killed him was possible due to an impossible balance of energy that made it so that he was born with all this and perfectly fine.
A proof of his special characteristic is how his wings are half golden and half black, a perfect mix of both powers that should not be able to coexist.
Based on that it was possible that when he finished growing up he would already be on the limit of Leader-class (the equivalent to one of the Chaos Gods in OEG), but the problem is that his mother was scared by the thought that there might be some that would start a war to kill her child due to various political motives, so she put on a seal in him.

The seal not only blocked off most of his Evil energy it also sealed his angelic powers and left him nearly crippled in the matter of power. His originally absurdly powerful magic circuits were weakened and damaged to a point where it was terrible beyond compare, the weakest of the weak, and his bright beyond compare and smooth future was cut short. To every magic that for others would be easy for him it would be hard and the pain he had to endure was greater than anyone else doing the same, but he stood tall and did it regardless. He tried his hardest and learned everything he could possibly do, every shread of technique or information about magic or physical training was already deep in his head as no one understood how much effort he truly put into it, but his powers were limited.

After losing an arm during a battle against Kokabiel he was used as a ritualistic object for the ritual to create Argetlan, his body now has not a drop of blood and all of it is instead the purest energy of the world itself, this made it possible for the seal in his body to be broken and he now has finaly regained his angelic and evil energies, but his magic circuits still are weak when comparying to what they should be, his potential still undecided.

Finally, a thing of notice is that due to all the knowledge Castiel have about various matters about magic, political, and leadership matters he already knows so much that some may even call him a genius about it, even if he can only be said to be a genius of hard work.

His unarmed combat capabilities are taught by him by Souichiru Kuzuki, his future father-in-law (yes, Castiel is the fiancée of Souichiru and Caster's daughter), and it is a stile named Serpent, it focuses in instantly killing the enemy or at least damaging the joints. Castiel is highly capable in it to the point that Souichiru once said that Castiel could potentially suppress him in just a few more years.

For swordsmanship he not only learned it with both Saber but also Assassin but also with a simulator build by the Tower using the information Shirou had about all manners of heroes of the past, Castiel was not a genius in the sword by any means but finding someone more capable than him with it was much harder than most understood.

He also learned about beast taiming with Rider, magecraft with Rin and Luvia, witchcraft and magic of the age of gods with Caster, runecraft with Lancer, and many other things.

Other thing of notice is the fact he currently have a total of four familiars. 2 of them are Cosmoems (a gem-like being with a sphere in the center that looks just like a galaxy), one Jirachi (a child-like creature with a head looking like a star), and finally Eevee (this one, I doubt need introduction, except for the fact it can evolve at will to any of its forms).

Relationships: Castiel values his relationships highly, he would not hesitate in the slightest to sacrifice himself for his loved ones or the Tower. He currently has friends with all kinds of species and is engaged with Miku Izayoi (Miku from Date a Live), Yuno Kuzuki (Yuno from Mirai Nikki), Kaguya and Yuzuru (the twins in Date a Live). He also is dating Seryuu (Akame Ga Kill), Serenity (an OC that is the reincarnation of Hassan of Serenity from Fate/Grad Order), and also is relatively close to a few other females.

Things he likes: getting stronger, capable people or that at least try, command, being with his loved ones, completing a mission perfectly, and pudding, never forget that one.

Things he dislikes: working with others he considers incompetent, failing at anything he considers he should be able to get it right, his mother, the hero faction as a whole, senseless violence against the innocent (as long as it is a sentient life), seeing those he considers his friends hurt in any way, and not being able to eat pudding for too long (one of his greatest happiness is that even when he eats way too much sugar his Left leg Spirit bone diminishes all negative effects of it, he can eat it without a shred of worry in his mind).