Killian (MCU)'s powers and abilities
Extremis enhanced Killian's muscles to the point of being able to tear several Iron Man Armors with his bare hands.
Extremis enhanced Killian's speed and agility to the point where he was able to effortlessly dodge many of Iron Man's repulsor attacks.
Regenerative Healing Factor
Killian was able to heal his previous disabilities, as it was the primary original intention of Extremis. He was able to heal superficial wounds almost immediately, regrow severed limbs in a matter of seconds, and even withstand powerful explosions.
Hosts of Extremis are able to consciously raise the temperature of parts of their bodies. The effect can be controlled to the extent that it might only scorch skin, or increased to the point where it can cause steel to turn into a molten state.
An advanced control of Extremis granted Killian the ability to breath fire, using it as an offensive power against James Rhodes when taking control of the Iron Patriot Armor.
Genius Level Intellect
Killian was a highly intelligent individual, known to be a genius while still young, and had an affinity for science. Initially being rejected by Tony Stark, Killian would self-improve his intelligence to the point that he managed to effectively start up A.I.M. and his Extremis project.
Killian had a natural gift for science ever since he was young and started to study many scientific fields in order to cure himself from his disability and manage to get revenge from Tony Stark, successfully becoming a great scientist. Alongside Maya Hansen, he was able to construct the Extremis, originally created to rewrite genetic code and allow to improve the performance of the human body.
Killian was an excellent businessman, as he was able to effectively manage A.I.M., a privately funded think-tank, and boost it to the point where it became one of the main Primary Systems Contractor for the United States Armed Forces and the United States Government.
Expert Martial Artist
During the battle of Norco, Killian proved himself to be highly accomplished in hand-to-hand combat, as he dueled Iron Man and was able to constantly outfight him by using his Extremis abilities to target vital parts in the Iron Man armor to allow him to destroy a number of them, eventually culminating in Killian destroying all of Stark's available armors and leaving him defenseless and at his mercy.