The latest updates and spoilers for "Avengers: Infinity War" reveal two major characters returning to the Marvel Cinematic Universe. Cast member Mark Ruffalo told Michael Rapaport during his podcast show that Hela and Ancient One will likely appear in the movie. The two characters made their MCU debut's in "Doctor Strange" and "Thor: Ragnarok" played by Tilda Winton and Cate Blanchett.

There is also a new theory regarding the location of the last Infinity Stone in the movie and Thanos heads to earth to claim its power and complete his Infinity Gauntlet.

Hela and Ancient One

According to Michael Rapaport, Ruffalo dropped both Swinton and Blanchett names after being asked about which actor he had the pleasure of working with that gave him a lasting impression. This led to comic book fans speculating that the latter has worked with the two actresses separately on the set of "Avengers: Infinity War," but the studio has not yet made any comments about it.

The Ancient One is Stephen Strange's mentor during the events of the "Doctor Strange" movie and she was killed by her former disciple, Kaecilius after obtaining a small fraction of Dormammu's power.

Hela is the evil older sister of Thor and the main antagonist in the "Ragnarok" movie. She has been rumored to return to the third "Avengers" film and she will join Thanos on his mission to collect all of the Infinity Stones to rule the universe.

Soul Stone's location leaked

Reddit username TheAscendedAncient claims that the location of the Soul Stone is inside the body of the Asgardian gatekeeper, Heimdall. Thanos and his Black Order are coming to Earth to hunt down Heimdall, Doctor Strange, and Vision for the three stones.

The Redditor is also responsible for posting the leaked HD photos of the sequel's first trailer and it featured Captain America's underground team fighting Proxima Midnight.

Cap must reunite Earth's Mightiest Heroes with Iron Man to stop Thanos and save the universe from the Stones' power.

The Guardians of the Galaxy are also present in the movie and comic book fans will love how these two teams interact and fight side-by-side against the invaders.

Marvel Studios head Kevin Feige told Collider that the third and fourth will feature several character changes as they want to evolve the heroes not just physically, but also emotionally to gain a new perspective on things. Feige pointed to Thor's missing eye and hammer as an example of that change to give him an interesting depth of his character.