Ragnarok was created in the early days of the superhuman Civil War by Reed Richards, Tony Stark, Criti Noll and later Baron Von Blitzschlag using DNA from Thor. The clone's purpose was to assist the Pro-Registration forces in place of, the then-dead, Thor. The clone was tested and eventually set to be deployed when the need for a Thor would arise.
Ragnarok was created by writer Mark Millar and artist Steve McNiven and first appeared in Civil War #3. He appeared throughout the Civil War event and it's crossovers and was later revived during the Dark Reign by Christos Gage.
Christos Gage (writer for Avengers: The Initiative)
He genuinely believes himself to be the real Thor. But he's got all the haughtiness and arrogance of a god without any of the humility Thor learned while living as Don Blake. He can't understand why these inferior being don't bow down before him and worship him like they're supposed to. And as a very young being, he also, to a certain extent, is like a kid--a sociopathic, extraordinarily powerful kid whose tantrums break cities in half.
Mayor Story Arcs
During a battle between pro and anti-registration forces, Iron Man unleashes his clone which malfunctions and kills Black Goliath. It is later revealed that the cloned thunder god was created by Reed Richards and "Hank Pym" from a strand of Thor's hair Tony found during a meeting with the original Avengers many years ago. The debut of the Thor clone affected both sides and killed Goliath with a blast through the chest during a battle. The fact that pro registration forces have such a powerful weapon at their disposal causes Nighthawk and Stature to switch sides, while Susan and Johnny Storm decide to oppose the S.H.R.A and join Cap's Resistance since Reed took part in its creation... During the final battle Hercules uses Mjolnir to defeat the clone after he battled Storm and Invisible Woman.
Ragnarok's damaged body later appears in the lab of Baron Von Blitzschlag. With the death of Criti Noll and the Skrull Invasion lost, operation "Final Strike" activates, repairing the android and unleashing it on Camp Hammond.
The combined forces of Thor Girl and the remaining Initiative members and the New Warriors were unable to stop Ragnarok until he's told that he is a clone of the true Thor and more importantly, that Asgard is on Earth. Outraged by this news, Ragnarok blames Thor for Asgard's current states, deciding that he must defeat Thor and set things right.
When the forces of Norman Osborn and H.A.M.M.E.R. came to conquer Asgard, Ragnarok traveled to Broxton, Oklahoma to engage Thor. He came across Thor's ally Volstagg, who initially mistook him for the actual Thor dressed in his old attire, before engaging Ragnarok.
The battle that followed lead to the fields lying beneath Asgard, who ultimately came toppling down on the dreaded android as the Sentry destroyed the foundations of Asgard. In the aftermath of the Siege, the Asgardians slowly began to rebuild. However, Volstagg and his comrades Hogun and Fandral came across the body of Ragnarok, who attacked them.
It was not long before the real Thor came to engage his clone head-on. The battle was fierce, but it proved of the true Thor's power over the "pretender," which ultimately destroyed the false God of Thunder. The menace of Ragnarok was no more.
Ragnarok was later retrieved by agents of A.I.M. who unfortunately did not have the financial backing to attempt to repair the cyborg. When A.I.M. joined forces with HAMMER, Monica Rappaccini offered Norman Osborn the clone as a gift for his team of Avengers. With the assistance of HAMMER, A.I.M. were able to repair and reactivate Ragnarok and reprogram him.
Ragnarok was sent to battle against the New Avengers on behalf of Norman Osborn and his Dark Avengers. After an intense battle between Ragnarok and the team, he was soon defeated by Iron Fist who, with help from Spider-Man, unleashed an awesome blow of force to the android and possibly once again destroyed the monster.
After Ragnarok's appearance as a member of Norman Osborn's Dark Avengers and his defeat at the hands of Iron Fist, Ragnarok was ordered to become a teammember of the supervillains-turned superheroes team known as the Thunderbolts.
Powers & Abilities
As a cyborg clone of Thor, Ragnarok has all the powers and knowledge of the God of Thunder, (prior to Thor's recent acquisition of the Odinforce) including super-strength, extensive combat knowledge, godly stamina, high resistance to physical injury, immunity to all Earthly diseases, and superhuman agility and reflexes. Ragnarok's hammer, though not the enchanted Mjolnir, is constructed of a vibranium and adamantium alloy. The hammer is able to absorb and discharge lightning, like the true Mjolnir, and has circuitry within its head, which allows Ragnarok to direct it mentally. However, unlike Mjolnir, it can be picked up or lifted by others.
In the world where Captain America lead all the heroes against registration, Henry Gyrich developed Project: Thunderstrike using the DNA Tony Stark had of Thor and created his own Thor clones to fight in favor of his far more fascistic Superhuman Registration Act. Ragnarok led an army of Thor-powered agents who killed a great amount of resisting superhumans such as the She-Hulk, Wonder Man and the Thunderbolts.
Earth-10208 (What If? Civil War)
In another alternate reality, during the Civil War, Ragnarok is unleashed on the Resistance much earlier than in the main reality and his attack leads to the two opposing sides banding together to defeat the false god.