Let's start with the American billionaire playboy, industrialist, and ingenious engineer that creates a powered suit of armor:
TONY STARK (IRON MAN)
He is who creates Ultron (the evil villain) with the possible help of his good friend Bruce Banner (HULK). The Stark Tower is now The Avengers Tower. He is gonna feel gulity and we will see a tense behavior with Steve Rogers (Captain America).
STEVE ROGERS (CAPTAIN AMERICA)
The World War II veteran enhanced to the peak of human physicality by an experimental serum and frozen in suspended animation before waking up in the modern world.
In this movie he is looking for a home and he feels comfortable with the others memebers of the team but there is a strange behavior with Tony Stark . He's looking to understand where he belongs as a soldier but also as a person.
NATASHA ROMANOFF (BLACK WIDOW)
A highly trained spy, formerly of S.H.I.E.L.D.
She will remember her past and we will discover unknown parts of her life.
There is a special relationship with Bruce Banner (HULK)
CLINT BARTON (HAWKEYE)
A master archer who previously worked as an agent for S.H.I.E.L.D.
He will interact more with the other characters in the film and he will have an important role.
BRUCE BANNER (HULK)
A genius scientist who, because of exposure to gamma radiation, transforms into a monster when enraged or agitated.
He is a good friend of Tony Stark (IRON MAN) and has a special relation with Natasha.
HULK will confront HULK BUSTER (a special armor of Tony Stark ready for a uncontrolled behavior of ''The Green Monster'')
The crown prince of Asgard, based on the Norse mythological deity of the same name.
In this movie he is a little more grounded and human and have him in some civilian clothes and mixing it up at a party.
He matured very much and has an important role.
PIETRO MAXIMOFF (QUICKSILVER)
The twin brother of the Scarlet Witch, who can move at superhuman speed. "He and his sister have been abandoned by their parents and their father, and they grew up in Eastern Europe defending and looking out for themselves and each other.
WANDA MAXIMOFF (SCARLET WITCH)
The twin sister of Quicksilver, who can harness magic and engage in hypnosis and telekinesis. She has such a vast amount of knowledge that she's unable to learn how to control it.
An android created by Tony Stark and Bruce Banner. Vision feels paternal and protective to a number of people in the film, particularly Scarlet Witch. He has the ability to fly and change his density and also,project intense energy beams.