Clint McIntyre was court-martialed after murdering his commanding officer but avoided punishment by agreeing to be experimented on by Project: Rebirth. Due to McIntyre's physical superiority to Steve Rogers, some of Project: Rebirth believed McIntyre was who should be receiving the Super-Soldier Serum over the frail and weak Rogers. One rebellious member of the team stole a prototype of the Super-Soldier Serum from it's creator Abraham Erskine and gave it to McIntyre who became incredibly strong and fast. However, McIntyre did not receive the complete treatment including the Vita-Rays and as a result he went mad and murdered several officers before collapsing from heart stress.
McIntyre was cryogenically frozen and eventually fell into the care of S.H.I.E.L.D. and remained in their storage for decades. When three S.H.I.E.L.D. agents were punished for botching a simple operation, they were tasked with cataloguing every item in S.H.I.E.L.D. storage and came across McIntyre. One of the agents, Clete Billups, was actually a double-agent working for A.I.M. and killed his co-workers in order to deliver McIntyre to A.I.M. for use as a weapon.
Awakening McIntyre from his long slumber with no real memories of his own, A.I.M. director Chet Madden fed him lies about his origin and manipulated him into believing Captain America had stolen his true destiny. They also convinced him that HYDRA, S.H.I.E.L.D. and their other opposition were enemies of America and rechristened their soldier as Protocide, arming him with a shield which slightly resembled that of Captain America.
Protocide was created by Dan Jurgens and Andy Kubert and first appeared in Captain America #26.
Protocide was one of the main antagonists in Dan Jurgens' run on Captain America. Protocide was introduced and his origin was a mystery which was teased and drawn out until Captain America Annual 2000 which detailed his beginnings. A retcon character, Protocide was inserted into Captain America's origin and was presented as having received the Super-Soldier Serum before the hero, making Protocide the first Super-Soldier. Although the comics featuring Protocide's origin clearly state this to be the case indisputably, Marvel have since distanced from retcons such as this to Captain America's origin and have denied anyone came before Steve Rogers (although without acknowledging Protocide at all). The character was last seen hitch-hiking following a battle between himself and Captain America and hasn't been seen since. He received an Official Handbook of the Marvel Universe entry in All-New Official Handbook of the Marvel Universe A to Z #8.
Major Story Arcs
U.S.Agent vs. Protocide, the Warm-Up Match!
After having performed well for A.I.M. in various training exercises and low-level missions, A.I.M. decided to send Protocide up against a superhuman to see how he fared. A.I.M. dispatched Protocide to help defend an A.I.M. base which was under attack by U.S.Agent, who had recently been targeting A.I.M. operations specifically.
Protocide attacked U.S.Agent and the two soldiers battled, although it quickly became a one-sided match when Protocide overpowered U.S.Agent. Brutally beating U.S.Agent to the floor, Protocide continued his barrage of attacks, pummelling the beaten Avenger with his shield and shattering U.S.Agent's shield with his own. Protocide departed, leaving a severely injured and broken U.S.Agent who was fortunate enough to be saved by S.H.I.E.L.D. and Thor.
Captain America vs. Protocide, Round 1!
A.I.M. next decided it was time for Protocide to go after Captain America and acquire a deadly biochemical weapon from S.H.I.E.L.D. known as the Omega Compound. Intercepting Captain America and a S.H.I.E.L.D. transport while the weapon was in transit, Protocide got distracted from his mission to steal the weapon and instead continued to attack Captain America.
Captain America, more interested in preventing an accidental release of Omega Compound, was distracted from properly fighting back and as such was beaten incredibly badly by Protocide. Barely able to pick himself up, Captain America lay on the ground, cuddling the canister containing Omega Compound to prevent it from release or falling into enemy hands. Having failed his mission to steal the weapon, Protocide was recalled by his A.I.M. masters before S.H.I.E.L.D. reinforcements arrived.
Badly beaten, Captain America and Sharon Carter began a quest to learn more about Protocide, in hopes of having some edge over him in the inevitable rematch. Captain America pointed out that the passion and ferocity of Protocide's attack meant that there was something personal between the two and noted Protocide's speech mannerisms seemed outdated.
When the resources of S.H.I.E.L.D. and the Avengers were unable to provide any information or clue as to Protocide's true identity, Captain America visited Cache, a self-professed "all-knowing" sentient computer, for answers. Cache revealed the full origin of Protocide, unbeknownst to Captain America at the orders of A.I.M. who wished Captain America to know to make him believe he had something to use against Protocide in battle.
Captain America vs. Protocide, Round 2!
Knowing the truth about Protocide, Captain America had a stronger resolve than ever to locate Protocide and take him down for wasting the opportunity given to him and perverting the Super-Soldier Serum. The two met again when Protocide was attacking a HYDRA base and fought once more. Although Protocide again proved to be the physical superior, but as the two fought over an experimental energy generator, Protocide almost fell into the machine but was saved by Captain America.
Confused by his perceived enemy's act of compassion, Captain America tried to talk Protocide down and offer him a chance to redeem himself. Although Captain America's attempts to reach Protocide were felt by the enemy, he responded in frustrated passion by throwing Captain America down into an experimental energy generator, and believing him dead.
Captain America vs. Protocide, Final Bout!
Returning to A.I.M., still affected by Captain America's words, Protocide began to question the story that A.I.M. had fed him and his memories slowly began to return, despite the efforts of A.I.M. to prevent this. Elsewhere, a maddened Captain America set out to attack an A.I.M. base to find Protocide again, this time arming himself with Compound Omega as a last resort to deal with the villain and A.I.M. if needs be.
The two men faced each other once more and as they fought, Protocide recognized the Compound Omega canister Captain America had brought which in turn made him realize that if Captain America was willing to sacrifice himself own life to stop Protocide, then Captain America is not the selfish manipulative villain that A.I.M. had told him.
Protocide saved Captain America from a crashing helicopter containing the director of A.I.M. who was trying to escape. As the helicopter came down, the base went up in flames, but not before Protocide managed to throw Captain America away from the explosion. When the dust had settled, Protocide was believed dead by S.H.I.E.L.D., but he had actually survived the explosion and opted to start a new life somewhere else.
Powers and Abilities
Protocide received an early version of the Super-Soldier Serum which greatly increased his speed, stamina and strength. Due to McIntyre's already peak physical shape prior to receiving the serum, it meant it amplified his already existing abilities, therefore making him physically superior to Steve Rogers. McIntyre didn't receive the Vita-Ray treatment which meant left him mentally unbalanced and caused a great strain on his heart, although A.I.M. appeared to have cured this through unknown means.
Protocide carried a chevron-shaped shield, of unknown composition or origin, which was mostly used as an offensive weapon to impale or throw at enemies. It was incredibly durable and was able to shatter U.S.Agent's Vibranium shield.