Real Name: Kevin O'Brien
Occupation: Engineer for Stark Industies
Identity: Secret
Legal Status: Citizen of the United States with no criminal record
Other Aliases: None
Known Relatives: Michael (brother)
Place of Birth: Unknown
Group Affiliation: None
Base of Operations: Long Island, New York
First Appearance: (Kevin O'Brien) IRON MAN #31, (as Guardsman I) IRON MAN #43

History: Kevin O'Brien was an engineer working for the newly-opened Lakani island plant of Stark Industries who came to the attention of Anthony Stark, when he invented a stun-ray that managed to harmlessly disperse a crowd of violent protestors. Stark invited O'Brien to transfer to Stark's main plant on Long Island, New York, and he accepted. Despite a careless streak that once caused the laboratory he was working in to explode, he became a close friend of Stark, and was soon appointed head of Stark's research department. On several occasions, O'Brien assisted Stark and his supposed bodyguard Iron Man, who was really Stark himself, notably against the Spymaster and the Espionage Elite, saving Tony' Stark's life on more than one occasion. Stark then decided to reveal to O'Brien that he was secretly Iron Man, and to build for him s second suit of armor for use in the event of an emergency. That emergency came a short time later, when Iron Man and his girlfriend Marianne Rogers were taken captive by the superhuman madman Mikas the Soulfather. Putting on the armor before it was fully tested, O'Brien fell prey to a malfunction in the cybernetic curcuitry controlling the armor which apparently stimulated the regions of the brain where rage and jealousy originate.

O'Brien found himself seized with sudden attraction for Stark's girlfriend Marianne Rogers, and became extremely jealous of Stark's power, looks and fortune. At the same time Simon Gilbert, then chairman of the board of Stark Industries' stockholders, grew alarmed that Stark was moving out of munitions production and mapped strategies with the board to seize controlling interest in the firm from its principal stockholder, Stark himself. O'Brien, clad in armor and calling himself the Guardsman, offered to aid the board in their plot against Stark. As a show of support, he agreed to quell a protest rally outside the plant. The Guardsman aimed his repulser rays at the crowd, injuring four protesters. Sickened by what he did, O'Brien turned on the renegade board members, roughing them up. But seeing Tony Stark's with Marianne Rogers caused him to once again become unbalanced and he went outside to vent his rage on the growing crowd of protestors. Stark donned his Iron Man armor and engaged the Guardsman in battle to prevent him from doing more damage. Losing, the Guardsman sought refuge in an experimental tank. In an attempt to stop him without hurting him, Iron Man trained his repulsor rays on the vehicle and accidentally hit its fuel supply. The tank exploded, killing Kevin O'Brien.

Height: 5 ft. 10 in.
Weight: 175 lbs.
Eyes: Blue
Hair: Red

Strength Level: Without his Guardsman armor, Kevin O'Brien possessed the normal human strength of a man his age, height, and build.

Known Superhuman Power: None

Paraphernalia: The Guardsman I armor specs are unknown at this time but it is assumed that they are similar to the Guardsman II armor.