Following a battle with the superpowered terrorist Mallen, Tony was left in critical condition, and his then-current suit of armor was badly damaged. He later informed Maya Hansen that he had been working on an upgraded prototype suit, one he hoped could collapse into an easily storable form like the older Iron Man models he'd used. Unfortunately, he had been unable to properly minimize the control systems needed to operate such an advanced machine, and still needed to wear an undersheath beneath it.
Sensing an opportunity, Tony injected himself with the Extremis serum, hoping to both heal his fatal injuries and get the new armor working. The serum transformed his body, allowing him to store the undersheath in the hollows of his bones and to control the new armor mentally. With the Extremis armor, Tony easily defeated Mallen.
Tony continued wearing the Extremis suit for the next couple of years, but was unable to operate it any longer after purging the Extremis from his system during Dark Reign. Stark resorted to using several older, lower-tech armors before officially replacing the Extremis suit with the Bleeding Edge Armor.
In Other Media
Adi Granov's Extremis design proved to be very influential for the Iron Man adaptations made after the comic was released.
The Mark III armor from the live-action film bears many similarities to the Extremis suit. This is not coincidental, as the armor was actually designed by Adi Granov, the same artist who created the Extremis suit in the comics. The similarities were taken even further with the Mark VI armor from Iron Man 2, which sported a triangular chest piece inspired by the one on the Extremis armor.
In Season 2, Tony gets a new suit of armor, the Mark II, which is visually based on the Extremis Armor. Later in the season, Tony injects himself with the Extremis serum, allowing him to interface with the armor directly, just like in the comics.
- The Extremis Armor is an unlockable alternate costume in the Iron Man video game from Sega.
- Iron Man wears the Extremis Armor as his primary costume in Marvel Ultimate Alliance 2.
- Iron Man wears the Extremis Armor as his primary costume in Marvel vs. Capcom 3, replacing his Modular Armor from the previous games.
- The Extremis Armor appears as Iron Man's default costume in Marvel Heroes.
- Hasbro produced a figure of the Extremis Armor in the Marvel Legends Terrax Build-a-Figure wave. A stealth variant was also released.
- Bowen Designs released a statue of Iron Man in the Extremis suit.
- The Extremis suit was featured in Diamond Select's Marvel Select line.
- Hasbro released a figure of the Extremis suit for the Marvel Universe line.
- Sentinel released a figure of Iron Man in the Extremis suit for the RE:EDIT line.