Gregory Stark

Dr. Gregory Stark is an original fictional character in the Ultimate Marvel Comics universe.

Fictional character history
Gregory "Greg" Stark is the brother of Tony Stark. Unlike his brother, Gregory is more competent and doesn't possess Tony's infamous lifestyle, one of the reasons he doesn't think too kindly of his brother. He also believes he deserved to inherit Stark Industries instead of Tony. Gregory was called by Nick Fury in activating "Project Avengers" in order to track down Captain America and find and defeat the Red Skull and A.I.M. He also supplied Fury with other Avengers: the re-programmed Red-Wasp, a Hulk-clone "Nerd Hulk", grown from Bruce Banner's mind and the Hulk's strength, as well as Tony's lost friend James Rhodes. He remained with Fury behind the scenes, observing the Avengers' battle against a nigh-invincible Red Skull at AIM HQ in Alaska and his fatal defeat by Captain America.

Gregory later confronted Nick Fury in a S.H.I.E.L.D. safe house, where he revealed that he knew Fury was responsible for convincing the Red Skull to come out of retirement in order to secure himself a position in S.H.I.E.L.D.'s employment, with the eventual goal of regaining his old title as Director. Fury doesn't respond to the accusation.

Gregory later participated in the Avengers' and S.H.I.E.L.D.'s war against a vampire epidemic, being brought in along with Tony to question the vampire hunter, Blade. Following the vampire eradication, Gregory found his brother severely wounded and was subsequently sent for immediate medical attention. Thereafter, Gregory worked with Carol Danvers and the Ultimates in apprehending Nick Fury for allegedly going rogue selling top secret superhuman research (mainly to North Korea, China and Russian governments) on the Black Market. However, it was revealed that Gregory was actually responsible for leaking the information and manipulated both the Ultimates and the Avengers into removing Fury and Danvers to become head of S.H.I.E.L.D. following a meeting with the President. On top of a Helicarrier above NY, Stark has Fury shot and killed, however, due to Fury and his Avengers taking Hulk-pills from the deceased Tyrone Cash, he is alive. They were defeated by Stark using his technology-based powers: advanced nanites. Gregory stuns the Avengers and jumps off the craft, teleporting himself to North Korea and leaving Fury defeated for now.

In a massive battle in North Korea, the Ultimates and the Avengers fought the rogue super-soldiers. Gregory Stark interrupted, attempting to reason with the heroes. Thor threw Mjolnir, which Gregory caught before shattering Captain America's shield. Tony and Gregory faced off, and Gregory almost killed his sibling, but when Tony disabled Gregory's nanites with an electromagnetic pulse from his suit, Gregory was rendered defenseless. Thor, summoning his Hammer, then struck Gregory with lightning, to the surprise of Tony. Gregory is severely burned and later declared dead. At his funeral, Tony is approached by a person named Jonathan Blackheaven, who told him that Gregory was a member of the Kratos Club, an organization consisting of the super-elite.

Powers and abilites
Gregory has a Nanite Fleet in his body, similar to his brother Tony. This imbues him with super-human strength and invulnerability.