Thor 3 will follow up after the events of Avengers: Age of Ultron.
The movie is set to follow the 'Ragnarok' storyline, which features the destruction of Asgard. In the last movie, Loki was seen posing as Odin on the throne in Asgard, but that could change when Thor returns home after the events of Avengers 2.
Is Thor 3 is the End of Loki
In the comics, Loki dies during Ragnarok – an event he helps launch – which could mean the Tom Hiddleston's character could rest for a while.
The website Movie Pilot speculates that in Thor 3 Ragnarok sees Loki and the fire demon Surtur march on Asgard. Thor manages to fight them off, but loses his hammer Mjolnir. After he deals with the fire demon, Thor will rip Loki's head off.
Hiddleston recently confirmed that he will play the lead in King Kong prequel Skull Island, which could turn into a universe of its own, in the lines of Godzilla, with the two movies possibly leading to a merger. With Hiddleston now leading his own franchise, it may mean the end for him as Loki for Marvel?
Nevertheless in the Marvel universe, every character has a way of coming back, and maybe he could return in a shorter role in either another Thor movie or a cameo in a Guardians of the Galaxy sequel.
Meanwhile, Movie Pilot reported a few new characters could feature in Thor 3, including Beta Ray Bill and Valkyrie.
According to the website, Thor's universe be expanded, and Valkyrie – whose job is to fly over – battlefields and select brave warriors who have died and guide them to Valhalla – might become part of the Thor franchise.
"She wields the Dragonfang. I think that is her sword. She has wielded a spear as well," The website said.