Cyttorak is one of principalities - magical entities of endless mystical powers. His origin is shrouded in mystery. Once he was worshiped on Earth, and by unknown circumstances was banished to outer-dimension known as Crimson Cosmos, within the Omniverse.
Cyttorak is stated (by marvel) to be an old abstract magical entity from several millenia to several billions of years old. He appears in one of his 2 known aspects.
First aspect is a God-looking one which is a source of power to sorcerers and powerful mystical entities like Dr. Strange, Ancient One, Dormammu, Umar, Zom ...
Second aspect is a Demon - looking one that empowers Juggernaut and which is titled as "His most destructive aspect". This title strongly refers that there are also other aspects of Cyttorak. And what's even more interesting, his most destructive was set free by monks who tried to summon Cyttorak to Earth again and this aspect was later imprisoned in the Crimson Ruby. So there is strong indication that aspects are sentient on there own. During Infinity War, Cyttorak commented that he actually prefers to be in a God-looking aspect. It was shown that after destructive aspect was imprisoned in the Ruby, Cyttorak himself transported the Ruby outside of the temple on occasions in order to find human avatars easier.
According to the Official Handbook of the Marvel Universe (#12, 2007), Cyttorak's Crimson Cosmos is an Outer Plane, a magical dimension which is the Cyttorak's essence himself and is not connected or is not concerned with what happens in Earth’s dimension (616) but it has been traveled by a few users with competent magical ability as Dr. Strange, Ian McNee and Magik only with the consent of Cyttorak.
Cyttorak participated in the Octessence, a wager between eight vastly powerful inter-dimensional beings who decided to find out which was the most powerful by giving a fraction of their power to eight human avatars that would fight in their honor. Each of them placed an item in their temples for someone to find, after the first item was found people would be magically drawn to the remaining seven. After Juggernaut did help the Avengers in a long struggle against the Exemplars by defeating most of them by his own means and then destroy the God-Machine, the Cyttorak’s avatar proved to be the victorious and the true winner of the wager.
The collapse of his temple is assumed to be the reason why the other Exemplars did not emerge after Cain Marko became the Juggernaut.
Cyttorak was one of the many beings who tried to recruit Dr. Strange.
Cyttorak (most destructive aspect) was later seen in New Excalibur, and most recently in Captain Britain & MI-13 #3 where he was released from a magical prison.
Upon finding out that Juggernaut has forsaken him for Kuurth, Cyttorak takes his power back from Juggernaut and gives it to Colossus.
Losing His Avatar
After each inheriting a portion of the Phoenix Force, Colossus and his sister Magik confront the destruction lord in the Crimson Cosmos, asking him to free Colossus of his burden. Cyttorak refuses on the grounds that Colossus' reign of destruction was like a perpetual feast to him and that he made for a far better avatar of destruction then his predecessor, Cain Marko. When the siblings threatened him with their new power, Cyttorak warns them that even 1/5 of the Phoenix Force was insufficient to even challenge him.
Later Illyana transports her brother in Limbo and, being the demon lord of that dimension, severs the bonds that enslave Colossus, freeing him Cyttorak's taint. It is unknown how Cyttorak will react to the loss of his latest, favorite avatar.
The Once and Future Juggernaut
The Crimson Gem of Cyttorak has returned to Earth and Cyttorak is looking for a new avatar. Previous avatars of Cyttorak, Cain Marko and Colossus have heard its call, but they are not the only ones. The mercenary Crossbones as well as Man-Killer have joined the party. Now it's up to the X-men to stop the gem from falling into the wrong hands.
Powers and Abilities
Cyttorak is an immensely powerful magical deity, who is omnipotent within his Crimson Cosmos. Powerful magic users such as Doctor Strange, The Ancient One, Dormammu and Zom have invoked Cyttorak's power. The Vishanti have shown at one point to be wary of angering Cyttorak and advised Doctor Strange not to intervene with Cyttorak or any of his creations. Cyttorak's energies grant his avatar virtually limitless strength and durability.
The fraction of his power given to the Juggernaut was stated by D'Spayre to be able to control the very fabric of the Universe itself. Plundering Cyttorak’s energies from Juggernaut, D'Spayre (a mighty Fear Lord) was boosted to a near-omnipotent state (reality warper), being able to warp the universe. Not to mention, D’Spayre used his new reality warping powers to create a portal to Oblivion and reduce the Juggernaut to skeleton at one point until an enraged Juggernaut managed to defeat him.
Cyttorak's magic has allowed Juggernaut incredible durability, even keeping him alive after being stripped to bare bones. According to the original canon written by Stan Lee, Oblivion has shown to be unable to kill Juggernaut by aging him or erase him into the void, confessing that his presence was an annoying infection inside of its void that could not be voided out of existence so he spat him out of his realm in exchange of a fraction of Cyttorak’s powers. This fact showed that Cyttorak has more influence on the Juggernaut’s existence than Oblivion even inside within Oblivion's own realm.
When his avatar Juggernaut learned some spells from Crimson Cosmos he was able to overpower demon Nightmare in his domain. At that time Nightmare imprisoned Eternity by forcing every sentient being in the universe to sleep, causing Eternity to fall in a dream state, which allowed Nightmare to control him and use his cosmic powers to destroy the Earth. However, given the inability of Dr. Strange to free Eternity, Juggernaut suddenly bounce into Nightmare’s realm by using certain magical skills of Cyttorak’s powers which he learned during his exile in the Crimson Cosmos. Juggernaut by using some spells of Cyttorak’s powers was able to neutralize and mock the powers of Nightmare (boosted with the cosmic powers level of Eternity) in his own realm. This feat proves that magical powers of Cyttorak could affect or neutralize the cosmic powers of the entity Eternity.
Cyttorak has demonstrated that he can create life from nothing, as he created an entire race of elves just to worship him in the Crimson Cosmos, and he also created magical servants in order to protect his temple in South Korea. Those who were invoking Cyttorak for power were granted a variety of spells, and each had a certain effect. Those spells are: Crimson Bands of Cyttorak, Scarlet Sphere of Cyttorak, Crimson Shields of Cyttorak, Crimson Crystals of Cyttorak, Cage of Cyttorak and others.
Cyttorak is a teleporter, once used his tendrils to capture the cosmic spaceship with Galactus, Silver Surfer, Nova and Doctor Strange on it and they were helpless against him. The tendrils teared through dimensions and sucked the spaceship into the Cyttorak's realm.
Recently Cyttorak overpowered 1/5 of the Phoenix Force which was in Colossus without any effort. This feat is not all that impressive though because the Phoenix Force has been driven away by a few members of X-Men and Ultra Force, and also that Cyttorak is absolutely omnipotent in his realm.
During the Trion Saga, the Trion's dark entity possessed the Juggernaut and tapped into Cyttorak's power to power up his avatar into an universe busting level on which he was able to crack through the very fabric of space-time itself, causing the break down of multiple dimensional barriers by punching them. When Cyttorak's energies got released from Juggernaut they started destroying the unearthly Universe of the powerful Trion Gods (creators of the Triple-Evil). The rampage of Juggernaut during the Trion saga left many dimensions merged together. This feat confirms and proves once again, that magical energies of Cyttorak could destroy a single universe. Not to mention Mephisto pointed out that Cyttorak is one of the closest candidates to be the true Satan.