Loki... Also the Trickster and the first obsticale in the story as he leaves asgard and Thor comes down to take him back home
The Mentor, Nick Fury, Head of S.H.I.E.L.D, calls in the avengers to retrieve the Tesseract .
The Shape-Shifter is Hawkeye..
When he gets charmed by loki he starts fighting aginst the avengers..
The Threshold Guardians
Loki sends an alien army to stop the avengers
But the Avengers obviously win against the aliens and get back the tesseract, and peace is restored. For now...
Staring: Robert Downey Jr. - Tony Stark / Iron Man Chris Evans - Steve Rogers / Captain America Mark Ruffalo - Bruce Banner / The Hulk Chris Hemsworth - Thor Scarlett Johansson - Natasha Romanoff / Black Widow Jeremy Renner - Clint Barton / Hawkeye Tom Hiddleston - Loki Clark Gregg - Agent Phil Coulson Cobie Smulders - Agent Maria Hill and Samuel L. Jackson - Nick Fury