Serpent

''My children. We must not fail. I told you all I'd reclaim you from the veil of tears, and so I have. And now you must be ready for your work. Go forth and bring my terror to this place. Spread my gospel across this tomb of a globe we remain trapped upon. Punish and terrify every single living thing you can. You must not tire and you must not fail... ... Show no mercy here; show no patience for these vermin. See them driven before you. Beat them and maul them and break them any way you know how. Do not stop. '''Make them tremble. Make them beg. Fill them with doubt and panic'''. And fear...''

Time Before Time
Cul Borson was an enigmatic being, who claimed to be the true all-father of Asgard. Little is known of his origins, as Odin kept his very existence secret from his fellow subjects. It has been implied he comes from a much earlier Asgard and did not reincarnate in later cycles. It is known that, while riding as a boy during the time that Earth was known as Aesheim, Cul was attacked by Giants and thrown off a peak. Breaking most of his bones, Cul splintered both his legs and belly-crawled to the camp of the slumbering giants, where he later tore the throats of each giant, save one, with his teeth killing them. For the one giant left, Cul left a message in blood stating that "Gods do not live in the sky. We live on the Earth. And you do so at our pleasure." Thus instilling fear in the giant which would spread giving birth to the god of fear.

Becoming the All-Father
After returning home to Asgard, Cul was watched-over by a young girl with green eyes. Cul grew to have feelings for the girl, but after he healed her, she had completely disappeared, which left Cul bitter. After the death of his father, Bor, a still young Cul proclaimed that he would be king, as he was the eldest son, and promised to keep his brothers, Odin, Vili, Ve, as his trusted council. However, Cul did not stick to his word and carried his Worthy as his closest aids and used them and his Draumar to spread fear all over the Nine Realms. Cul's brother's worked to stop the beasts that Cul released on Aesheim, but Cul confronted them, telling them to go home and allow him to rule.

Silenced and Forgotten
Many centuries later, Cul ruled over Aesheim, spreading fear, until his brothers approached his citadel. Odin slaughtered all of Cul's followers, on his way to the main chamber. Locked away in the main chamber, Cul began to experience a new sensation, fear, for the first time in his life. As Odin drew near, Cul reassured himself that Odin could not kill him, as the ancient rules prevented it, and transported his Worthy away, telling them to await his call. As Odin entered the chamber, Cul proclaimed himself the Serpent and stated that Odin could not kill him due to ancient rules. Odin then stated that Yggdrasill, the World Tree, had given him a vision that stated "In anger smites the warder of Earth, forth from their homes must all men flee; nine paces fares the son of Odin, and slain by the serpent, fearless, he sinks." Unable to kill his brother, Odin did defeat Cul and sealed him deep beneath the ocean. In order to end Cul's hold on the mortals, Odin began to kill all of them, in their hopes that with them and the memory of the Serpent gone, their fear would not empower Cul, and renamed Aesheim Midgard but spared the remaining who aren't aware of Cul's existence on their world.

Return
Many thousands of years later, Cul was freed from an ancient prison, by Sin, after possessing the Hammer of Skadi. Looking extremely old and frail and now called the Serpent, Cul prepared Sin's forces and called the hammers of his Worthy, to spread chaos and fear across the globe.

The hammers of the Worthy found suitable hosts and possessed them and, as the Worthy wreaked havoc and destruction around the world, the Serpent gained strength, transforming himself into a more youthful version, in addition to his staff transforming into a hammer. Almost immediately after gaining his new form he transformed a patch of Antarctica into Dark Asgard, a darker, hellish version of Asgard with its own version of Heimdall, a creature with thousands of eyes.

Following the new Asgard's creation, Thor arrived back on Earth and on the warpath to find the Serpent. The all-seeing creature alerted the Serpent to the coming of Thor and Cul dispatched his forces to greet the Thunder God, after which the Serpent revealed to Thor that a prophecy stated that it was indeed Cul who Thor slays and dies as a result, not the Midgard Serpent. Further revealing relation to Odin, as his brother, and Thor, as his nephew, Cul tried to convince Thor to join him in his cause, which Thor promptly refused, forcing the Serpent to teleport Thor away to where two of his Worthy, Nul: Breaker of Worlds, possessing the Hulk, and Angrir: Breaker of Wills, possessing the Thing, were waiting to battle the Thunderer. Teleporting himself there shortly after, Cul joined Skadi in battle against the Avengers, where the Serpent easily pushed back the team and even intercepted an attack from Captain America's shield: breaking the shield a moment after. The Serpent then raised his hammer high and slammed it upon the Earth, obliterating the city in a devastating attack and disappearing amid the blast's wake.

Attempting to destroy Odin for stealing the right of the Asgardian throne, Cul and his new Asgard, full of his followers, journeyed to Broxton, Oklahoma, home to Thor's fallen Asgard, in an attempt to use Heimdall's Observatory to journey to the true realm eternal, Asgard. After Thor was healed and returned from Asgard, Cul switched to a giant serpent form and battled his nephew, while the Avengers fought the Worthy. At the end, Thor slayed his uncle with Odinsword, revealed to be Ragnarok, and died in the arms of his father, thus fulfilling the prophecy.

The day after the battle, while the Avengers prepared Thor's funeral, Odin took his brother's corpse to Asgard, cast-out all the other Asgardians, and locked himself alone with the body to guard it until the end of times, while blaming himself for not saving his son from death.

Powers and Abilities
Cul possessed all the conventional attributes of an Asgardian God. However, as the son of Bor, many of these attributes were significantly superior than those possessed by the majority of his race.

Superhuman Strength: In spite of his advanced age, Cul possesses superhuman strength surpassing that of most Asgardian's who are capable of lifting 30 tons. Cul is capable of lifting over 100 tons. He's also able to augment his strength to even greater heights by tapping into the fear of others.He has shown amazing feats of strength, such as breaking Captain America's shield with his bare hands.

Superhuman Speed: Cul, despite his age, was capable of running and moving at speeds greater than even the finest human athlete capable of speeds rivaling most superhuman's in spite of his age.

Superhuman Agility: Cul's agility, balance, and bodily coordination, were far superior to the natural physical limits of the finest human athlete.

Superhuman Reflexes: Cul's reflexes, were much more superior to the natural physical limits of the finest human athlete.

Superhuman Stamina: Cul's musculature produced considerably less fatigue toxins during physical activity than the musculature of a human, and most other Asgardians. As a result, he possessed superhuman stamina in all physical activities. He could exert himself at peak capacity for months before fatigue would begin to impair him.

Superhumanly Dense Tissue: Cul's skin, muscle, and bone tissues were about 3 times as dense as those of a human beings, this contributes, in part, to Cul's superhuman strength and weight.

Superhuman Durability: Cul's body was considerably more resistant to physical injury than the body of a human being, or even most other Asgardians for that matter. Cul's body was capable of withstanding great impact forces, exposure to temperature and pressure extremes, falls from great heights, and powerful energy blasts from cosmic level beings without sustaining injury, however, though to what extent is unknown.

Regenerative Healing Factor: Like all other Asgardians it was possible to injure Cul, but he recovered from injury with superhuman levels of speed and efficiency, Cul was capable of regenerating massive tissue damage or loss to a degree far beyond that of most other Asgardians, even of being able to regenerate missing limbs and organs, faster and with much more efficiency. Cul's healing powers were far superior to all other Asgardian Gods. Magical Manipulation: Cul can manipulate vast quantities of magic for nearly any effect. A few demonstrations of his power include transporting Thor far away, creating his own twisted version of Asgard, raising and recreating dead servants, turning into a giant serpent, and destroying a majority of the buildings in Manhattan.
 * Extended Longevity: Cul, like all Asgardians, was extremely long-lived, although not truly immortal as some other god pantheons. However, Cul still aged at a pace much slower than human beings. He was also immune to all known Earthly diseases and infections.

Fear Eating: Unlike other Asgardian gods Cul can feed upon the fears of others to empower himself. The fear of an entire world is necessary for him to be a full power. It is unknown if he needs to feed constantly or if periodic feedings are enough when he is not using his powers. The more fear he consumes the younger and more vigorous his body becomes.