Desmond Pitt was in the army with Benjamin Grimm and after they mustered out they both became test pilots. After later re-enlisting, Pitt discovered several agents of Doctor Doom had infiltrated NASA. He decided to infiltrate them in turn.
When his wife died he got careless and was discovered and seemingly executed. Instead of killing Pitt, Doom turned him into the cyborg known as Darkoth, the Death Demon.
As he hadn't been able to confide in anybody, fearing Latverian spies everywhere, it seemed to the military that Pitt was a traitor.
After heroically sacrificing himself to save the life of the Thing, Pitt's soul was snatched by Mephisto before it reached its true destination. Mephisto, who was jealous of Thor's prior victory over him, called upon Darkoth (Pitt) to take the soul of Donald Blake (Thor's alter-ego) in return for his own soul. Pitt agreed, but only so he could return to his son, who was in an orphanage at the time. When Darkoth confronted a sleeping Blake he found himself unable to kill an innocent man and refused to do so. Mephisto intervened and forced Pitt to fight Thor for Blake's soul. Thor was victorious and even managed to free Darkoth from Mephisto's grasp by purging him of evil with his lighting and sending him to the afterlife. Afterwards, Donald Blake arranged for Pitt's son to be adopted by his new secretary and her husband.
Darkoth was a cybernetic organism further mutated through chemical means. As a result, he possessed a variety of superhuman abilities.
Superhuman Strength: Darkoth's chemically enhanced musculature granted him superhuman strength sufficient to lift about 50 tons.
Superhuman Speed: Darkoth was capable of running and moving at speeds superior to that of the finest human athlete. He could reach a top speed of about 60 miles per hour.
Superhuman Stamina: Aside from being superhumanly strong, Darkoth's chemically enhanced musculature produced considerably less fatigue toxins during physical activities than the musculature of normal humans. He could physically exert himself at peak capacity for about 24 hours before the build up of fatigue toxins in his blood began to impair him.
Superhuman Agility: Darkoth's agility, balance, and bodily coordination were enhanced to levels that were beyond the natural physical limits of even the finest human athlete.
Superhuman Reflexes: Darkoth's reflexes were similarly enhanced and were superior to those of the finest human athlete.
Superhuman Durability: Due to a combination of cybernetics and chemical mutation, Darkoth's body was considerably resistant to physical injury. Darkoth's thick purple hide could withstand the impact of high caliber bullets, artillery cannon shells, and exposure to temperature extremes, such those generated by re-entering Earth's atmosphere, without sustaining injury. Darkoth's bones had been replaced with an unnamed, highly durable steel alloy. Much like his skin and musculature, Darkoth's cybernetic skeleton could withstand powerful impact forces and exposure to temperature and pressure extremes without sustaining damage.
Flight: Attached to each of Darkoth's feet was a single pair of small, bat-like wings that allowed him to fly slowly through the air for brief distances.
Tail: Darkoth also possessed a reptilian-like, prehensile tail that he used primarily for balance, adding onto his already superhumanly enhanced agility.Firehorns: Darkoth had two antennae on his head referred to as firehorns that had a few unique attributes. Through some unknown means, the firehorns fed on the mental energies of Darkoth's opponents at a maximum range of about 50 feet. The firehorns were also capable, when fully charged with energy, of emitting beams of intense heat capable of burning through several tons of ordinary steel within a matter of seconds. Lastly, the firehorns could fire heatless rays of concussive force powerful enough to knock down the Thing, and stun him.
Darkoth was a highly skilled pilot, due to his years of training and experience as a pilot for the United States Air Force. Darkoth was also a formidable hand to hand combatant, also mostly due to his time spent in the military.