IRON MAN
Tony Stark is a billionaire industrialist and inventor, and son of Howard Stark. During a weapons presentation in Afghanistan, Tony was severely injured and captured by the Ten Rings, who ordered him to build the Jericho missile for them to use. Instead Stark, with Ho Yinsen, used their resources to build a suit of armor and make their escape. Upon returning to America, Stark shut down the weapons division, made improvements for his armor and became the superhero Iron Man. Stark is one of the richest, smartest and most powerful men in the Marvel Cinematic Universe. His power derives from his high-tech battle suit known as the Iron Man Armor, which grants him extraordinary strength, durability, flightcapabilities and various on-board weaponry.
Fresh off from defeating enemies the world over, Stark reluctantly agreed to serve as a consultant to Nick Fury's peacekeeping intelligence agency S.H.I.E.L.D.. With a global crisis on the horizon and the fate of the world in the balance, Stark must power-up his Iron Man armor to save the world, and become a member of the Avengers. Usually when not on his own or with the Avengers, he teams up with his best friend and partner, Iron Patriot/War Machine.
THE HULK
Bruce Banner is a genius scientist who, due to exposure to gamma radiation, transforms into a super powerful green monster known as The Hulk at times of anger, stress or great danger, whenever his heart beats at intensified speeds. He is the one who tried to recreate the Super Soldier Serum which created Captain America decades before, but due to exposure to high levels of gamma radiation instead of vita-rays, resulted in Banner transforming into the Hulk. As the Hulk, Banner possesses an nearly unlimited degree of strength, speed, durability and regenerative capabilities that increases whenever he is even angrier, hence the old saying "the madder he gets, the stronger the Hulk becomes."
When a mounting threat calls for Banner's specialized scientific expertise, S.H.I.E.L.D. Director Nick Fury recruits him, knowing full well that the incredible strength of Banner's alter ego, the Hulk, would be an additional asset to the Avengers. After the Avengers split up, he became good friends with Tony Stark and was also given the freedom to live in the world without being hunted down.
THOR
Thor Odinson is an Asgardian warrior-prince, the God of Thunder and a self-proclaimed protector of Earth. He is the only Avenger that is non-human and one of the few superheroes in the MCU with genuine super powers (the others being the Hulk and Captain America). Thor wields the mystical war hammer Mjölnir, which controls the weather, but he himself also has godlike strength, durability and agility.
Thor was banished to Earth because his irresponsible behavior threatened his homeland and almost re-ignited a war between the Asgardians and the Frost Giants of Jotunheim. While in exile on Earth, Thor learned humility and helped to save his new friends from a destructive threat sent by his jealous adoptive brother Loki. In the process, Thor redeemed himself in the eyes of his father, Odin, and reclaimed his powers After being welcomed back to Asgard as a hero, Thor must now return to Earth once again to prevent a cosmic-level catastrophe. He soon finds himself drawn into an unlikely alliance with Nick Fury's secret initiative, the Avengers, lending his power to their cause against Loki and his army.
HAWKEYE
Clint Barton aka Hawkeye is a S.H.I.E.L.D. agent and founding member of the Avengers. He has no real superpowers, but is a skilled marksman with an exceptional ability in archery, normally armed with a recurve bow. In battle, Barton seems to be confident on his abilities. He even went as far as not to look at his target. Assigned by Nick Fury to watch over the Tesseract, he was brainwashed by Loki during the destruction of Project P.E.G.A.S.U.S.. However, after the Attack on the Helicarrier, he was freed from Loki's mental control by Black Widow, and joined the Avengers to fight against Loki's alien army in the Battle of New York, ending the War for Earth.
