Superhuman Strength: An Extremis subject's strength can be increased to superhuman levels, providing the user enough strength to toss cars and people with relative ease, break someone's skull with a single punch, counter Iron Man's superhuman physical blows, break Iron Man's bones with ease through the suit, rip the highly durable suit apart without effort, and even use the "blade" of a bulldozer as a blunt force object.
Superhuman Speed: An Extremis subject can move and run at incredible speeds up to 300mph, although it is unknown if this is the top speed an Extremis subject can move at.
Superhuman Stamina: The nanobots provided Mallen with almost unlimited stamina, with no need to eat, drink or breathe air.
Superhuman Durability: Extremis-enhanced beings have greater resistance to physical injury than an ordinary human. They are able to withstand bullet impacts and direct fire of Repulsor Blasts without feeling pain, at a potency higher than which a Repulsor Blast needs to have to cut through metal, only suffering minor wounds. Iron Man's uni-beam only caused Mallen great discomfort without injury.
Fire-Breathing: At the user's discretion, his/her lungs fill with fire plasma which he/she can exhale through his/her mouth. Mallen torched a lobby full of people through this method.
Claw-like pincers: An Extremis subject can unsheathe stings from his/her fingertips. They are very durable, and in conjunction with super-strength, they can be used by the Extremis subject to claw through a converter box.
Electrical discharge: Extremis-enhanced beings are able to discharge extremely powerful electrical currents through his/her hands which seemed to emanate from his chest through his arms.
Healing Factor: Extremis-enhaced beings can also heal wounds at a incredible speed, in a matter of hours.