Extremis is an advanced form of genetic manipulation created by Maya Hansen and Aldrich Killian, using nanotechnology. It grants the human body the ability to heal and regenerate from physical damages, deformities and even psychological damages. This also includes the regrowth of severed limbs in a very short timespan, various physical enhancements as well as an exothermic ability.
Used by A.I.M.
Extremis was created by Maya Hansen in 1999 and was first tested on plants, with Tony Stark providing additional aid through a formula he deduced to help reduce the volatility. Hansen and Aldrich Killian later upgraded Extremis thanks to Advanced Idea Mechanics providing additional funding for it to begin experimental testing on human subjects. A.I.M. recruited amputees and other disabled people for the trials, most notably victims of military ops. Successful transfusions of Extremis cured their disabilities, after which they were convinced to work for A.I.M. as assassins and soldiers. However, the subjects whose bodies rejected the treatment exploded since the glitch in the code wasn't completely neutralized. At the end, most, if not all of the Extremis Soldiers, were killed by the combined forces of Tony Stark, James Rhodes, and J.A.R.V.I.S..
Extremis was also used as the main component of a serum, designated by the clandestine program Centipede, that combined it with Gamma Radiation, a variation of the Super Soldier Serum and technology from the Chitauri for injection in an effort to create their own super soldiers. The Extremis component was stabilized when Centipede recruited Chan Ho Yin/Scorch. Before his death, they were able to drain some of his blood, as the platelets prevented him from being burned by his own pyrokinesis. Mike Peterson, after recovering from being knocked out by an I.C.E.R., discovered that he was now stabilized.
Extremis enhances the user's physiology by rewriting their DNA. It harnesses the body's bio-electricity and uses it to activate parts of the brain that govern repair and chemically recode them. This can allow Extremis to hack into the basic operating system of living organisms. If the user's body chooses to accept it, they will gain regenerative healing abilities, enabling to heal all wounds, including previously-amputated limbs or even physiological damage. When regenerating lost body parts, the wounds take on the appearance of burning embers while growing back the limb in a matter of minutes, and then cools into regular flesh, blood, and bone. Extremis also enhances physical performance, granting superhuman strength, reflexes, and overall higher resilience.
Additionally, normal Extremis users gain the ability to generate extreme amounts of heat through a complex metabolic process, with temperatures of up to several thousand degrees Celsius. Extremis users are able to consciously control the amount of heat expelled from their body, causing the area of their body generating it to glow intensely, superheating their tissues, blood vessels and nerves, while outlining them inside the body. This effect has been shown to be unstable in the event of an Extremis overload, burning the flesh and causing an explosion. Trained Extremis users can focus and conduct heat through a single area of their body such as their arms or hands, and even emit fire from their mouths, though it would seem that only the most disciplined of Extremis users can perform this feat. Certain users also demonstrated the ability to conduct heat through other objects with physical contact, allowing them to superheat targets by touching them.
Through a combination of superhuman strength and a focus of extreme heat conduction through their arms and hands, Extremis users can strike through and destroy a majority of metal structures on contact. Due to this, they are able to overpower and burn through the metal alloys that are used in most Iron Man armors, easily destroying many of the suits in combat.
Extremis users can be easily recognized through thermal imaging as they have a much higher heat signature. They can also be identified when their pupils glow while using their powers. Extremis does not make its users entirely invincible, as direct wounds through the chest, such as a uni-beam, will be lethal, destroying the victim's heart and therefore cutting off blood flow to the brain. When the body is regenerating, it is fragile and can be destroyed with a powerful enough force such as a repulsor shot. Destroying the users' brains and major organs through incineration has also been shown to be fatal.
The main weakness of Extremis is the possibility that its user's body will reject the serum upon initial injection, or that the serum may become unstable within the user if they fail to properly regulate their usage of it. Extremis users are able to consciously control the amount of heat expelled from their body, but this effect has been shown to be unstable in the event of an overload within. If the virus is not accepted by or regulated in the human body, the metabolic process which causes the user to generates excessive heat heat and the bio-electricity harnessed by Extremis will overload. As a result, the user’s will rapidly build up energy and force, cumulating in a massive explosion and powerful shockwave. The resulting explosion is an excess of 3,000°C and instantly vaporizes the Extremis user's body, along with anything within a certain proximity, leaving behind shadow-like marks of A.I.M. created several terrorist attacks on United States soil to cover up the explosions caused by Extremis test subjects.
- Aldrich Killian
- Extremis Soldiers
- Jack Taggart
- Chad Davis
- David Samuels
- Drew Grey
- Pepper Potts (unwillingly and stabilized)
- Tony Stark
- Michael Peterson (through Centipede)
- Chan Ho Yin (through Centipede)
- Brian Hayward (through Centipede)
- John Garrett (through Centipede)
- Daisy Johnson (through Centipede)
Behind the Scenes
- Executive producer Jeffrey Bell explained that the idea of using Extremis as part of the first season of Agents of S.H.I.E.L.D. came up independent of Iron Man 3, but the crew realized that it was a good opportunity to tie-in with the Marvel Cinematic Universe films, leading them to work with Marvel Studios to ensure that "they didn't feel like we were just ripping off their idea".