Loki's History
Loki himself is not a member of the Asgardians, but is actually the son of Laufey, the deceased monarch of the Frost Giants, the ancient enemies of the Asgardians. Odin himself led the Asgardians into battle against the Frost Giants and killed Laufey in personal combat.
After slaying Laufey, Odin found a small Asgardian-sized child hidden within the primary stronghold of the Frost Giants. The child was Loki, and Laufey kept him hidden from his people due to his shame over his son's small size. Odin took the boy, out of a combination of pity and because he was the son of a worthy adversary slain in honorable combat, and raised him as his son alongside his biological son Thor.
Throughout their childhood and into adolescence, Loki was resentful of the differences in which he and Thor were treated by the citizens of Asgard. The Asgardians valued great strength, tenacity, and bravery in battle above all things and Loki was clearly inferior to his foster brother Thor in these areas. However, Loki's gifts lay in other areas, most notably sorcery. Loki possessed a natural affinity to command great magical forces and hoped to somehow use these powers to become the most powerful god in all of Asgard and to destroy Thor.
As Loki grew to adulthood, his natural talent for causing mischief would manifest itself and earned himself a nickname as the God of Mischief. However, instead of playing harmless pranks, his deeds grew steadily more malicious and his lust for both power and revenge was apparent to all those around him. In time, his nickname grew from being a playful and mischievous trickster god to the "God of Evil".
Over the centuries, Loki would try to seize rulership of Asgard and to destroy Thor on many occasions. Odin, who had long tolerated Loki's attempts, magically imprisoned Loki within a tree. Loki would eventually free himself from his prison and his thirst for power and vengeance became even more consuming than it had ever been, if that were even possible.
Loki and Thor would clash more and more times, sometimes with Loki confronting Thor directly and sometimes using various pawns in order to achieve his ends. Among Loki's more well known henchmen was the human criminal Carl "The Crusher" Creel, whom Loki would use his sorcery to transform into the superhuman criminal known as The Absorbing Man, who himself would prove to be a formidable adversary to Thor over the years. Loki would even go so far as to attempt to turn Odin against Thor and to steal Thor's enchanted hammer, Mjolnir, all of which failed.
Loki's schemes would eventually come to include Earth itself and these schemes would often draw some of Earth's superhuman heroes to defend Earth and, often, Asgard itself. Loki was able to manipulate the Hulk into wreaking havoc and, accidentally, would lead to the formation of the Avengers. To make matters worse, Thor would be one of the founding members of the superhuman team and often found himself undone by them, many times, even when it seemed that his goals were within his grasp.
However, despite Loki's loathing for Thor and Odin, Loki would help to defend Asgard from destruction from Surtur and his fire demons. However, this was only because Surtur's goal was to destroy Asgard and Loki sought only to rule it.
It has been prophesied that Loki will lead Asgard's enemies into the "Eternal Realm" and aid them in destroying it in a final conflict known as Ragnarok, or sometimes referred to as "The Twilight of the Gods".
Loki fulfilled the prophecy of leading the enemies of Asgard against the Asgardians. This battle consumed all who participated in it and it was revealed that the cycle of the birth, lives, and death of the Asgardians was a continuing cycle presided over by beings known only as "Those Who Sit Above". Thor, Loki's foster brother and monarch of the Asgardians after Odin perished in battle against Surtur months earlier, was able to put an end to this continuing cycle. All Asgardians perished in this last Ragnarok except for Thor who would disappear into a deep sleep. But this time "Those Who Sit Above" followed them in death and were unable to revive them. Whether the Asgardians will receive a reincarnation after this final battle is uncertain.
In recent comics, as a bit of a sidebar to the Civil War arc, Mjolnir has returned. Whoever is able to lift the hammer will become the next Thor. The US Government had recovered it initially (actually they set up a base around it since they couldn't move it) but it is now a bit of an attraction for those seeking its power, beginning with Doctor Doom. It was finally lifted by a mysterious man, identified only as D. B., and both disappeared in a flash of light. Thor finally returned at the end of Civil War #3. There has been no indication of how this affects Loki, but it is likely he will also return in a new form.
