Origin

The Skrull who became known as the Super-Skrull was born with the name Kl’rt on Tarnax IV. Kl’rt volunteered to be artificially augmented at the command of Emperor Dorrek who had vowed revenge after an invasion of Earth was foiled by the Fantastic Four.

Kl’rt was given the combined abilities of the Fantastic Four, yet his powers exceeded the originals, he burned hotter and flew faster than Johnny Storm, he could stretch further than the Reed Richards, he exercised greater control over his invisibility and force fields than Susan Richards, and was stronger than Ben Grimm. Kl’rt retained his Skrullian shape-shifting abilities and his naturally strong hypnotic skills. He was dubbed the Super-Skrull by the Emperor himself, and was to be the point man in a second invasion of Earth. All he had to do was defeat the Fantastic Four.

At their first encounter Super-Skrull is able to hold an advantage over the Four until Reed correctly deduces that Kl’rt’s power is being further augmented by a beam directed from the Skrull homeworld. With the beam blocked Super-Skrull is quickly defeated.

Kl’rt attempts to avenge this humiliation many times by returning to Earth and battle such heroes as Spider-man, Captain Marvel, and Thor. He is soon trapped for several years in the Van Allen radiation belt by Ms. Marvel.

At some point while trapped he was used in plot of Master Khan against Iron Fist in which he is brainwashed into believing he is a twelve year old boy who can transform himself into “Captain Hero”, when he seemingly kills Iron Fist Khan returns him to the radiation belt with no memory if the incident.

The imprisonment has the beneficial effect of shielding Kl’rt from Zybak’s disaster, in which the entire Skrull race lost their shape-shifting abilities. After being freed from the radiation belt by the Silver Surfer, Kl’rt joins forces with S’byll, a claimant to the Skrull throne. She uses a sample of his DNA to restore the shape-shifting gene to the Skrull race. Lauded once again as a hero of the Skrull Empire he becomes the consort to the newly crowned Empress S’byll, but when the Empire falls once again into chaos when S’byll is betrayed by Captain Reptyl, who seemingly kills Kl’rt in single combat.

Kl’rt instead fell into a comatose state as his body recuperated. Gaining revenge on Reptyl, but finding the Empire in disarray, Kl’rt flees to Earth, where he goes into hiding. He maintains his secrecy for several months, but is drawn out by his need for revenge against the Fantastic Four, who summarily captures him and imprisons him in the Vault.

He escapes and renews contact with the Skrull Empire, he attempts to bring the Young Avenger, Hulkling (who is the son of Kree Captain Mar-Vell and Skrull Princess Anelle) into protective custody, but in a stroke of genius he impersonates Hulkling (with his consent) and puts himself in a prime position to spy on both the Kree and Skrull Empires.

Recently, Super-Skrull attempted to single-handedly defend the Skrull Empire from the Annihilation Wave and its planet killing super-weapon: The Harvester of Sorrows, he seemingly succeeds at the cost of his own life.

This appears later to be simply another period of recuperation for him as he fully recovers; is seen assisting Ronan in freeing the Kree Empire from House Fiyero.

Powers

The Super-Skrull has all the abilities of the original Fantastic Four, Mr. Fantastic's elasticity, Invisible Woman's invisibility and force fields, Human Torch's flight and pyrokinetics and the Thing's strength and rocky hide. Kl’rt also retains his Skrullian shape-shifting abilities and also has naturally strong hypnotic skills and a healing factor.