Though the Avengers: Endgame, which included the destruction of the Infinity Stones in the main MCU timeline, there is still a chance that the stones could return in Marvel's Phase 4 movies and TV series. Avengers: Endgame shows the defeat of Thanos (Josh Brolin), and the elemental crystals that were the MacGuffins of the narrative are no longer present in the primary universe. This doesn't mean, however, that they won't factor in any projects in the franchise.
After Thanos successfully collected all six Infinity Stones from the main MCU timeline and used them to eliminate half of life in the universe in Captain America's (Chris Evans) final mission, leaving primary reality devoid of any Infinity Stones.
As Marvel Studios move forward with a mix of projects for Phase 4, it's safe to say that they're once again building towards an overall narrative similar to what they did with Infinity War. Despite this, there are still several movies and TV shows in their pipeline where some of the Infinity Stones can factor in.
Space Stone in Loki
As part of the time heist in Avengers: Endgame, Iron Man (Robert Downey Jr), Captain America, Hulk (Mark Ruffalo), and Ant-Man (Paul Rudd) went back to the Battle of New York from 2012's Loki.
Production for Loki has been in full swing until the Time Variance Authority in the series, chances are that Thor's (Chris Hemsworth) brother is using the Space Stone to travel to different times and places. This means that the the Tesseract will play a major role in Loki's new adventures in his own TV series.
Mind Stone in WandaVision
Star-crossed lovers Wanda (Elizabeth Olsen) and Vision (Paul Bettany) have their own Disney+ series in Doctor Strange and the Multiverse of Madness, with Wanda also set to appear in the Benedict Cumberbatch-led sequel now directed by Sam Raimi. Fans got a brief look at what to expect from the series thanks to Marvel's big Super Bowl spot this year where the couple is seen mimicking various iconic sitcoms through the years.
Both heroes' powers came from the Mind Stone. Wanda and her twin brother, Pietro Maximoff/Quicksilver (Aaron Taylor Johnson) were experimented on by Hydra using the gem, while Vision was essentially powered by the same crystal when Tony Stark created him in Wanda's rather underutilized powers, and since Vision wasn't among those who were brought back to life in Endgame, questions regarding how he's back in the series remain. If Wanda attempts to bring her lover back, she might need Mind Stone or at least find another power source similar to how it functioned for Vision.
Time Stone in Doctor Strange in the Multiverse of Madness
Doctor Strange revealed the Time Stone, known as the Eye of Agamotto, as the Master of the Mystic Arts' most powerful weapon, which he used to trap Dormammu in a time loop during the film's climax. Sworn to protect the Time Stone, Strange was forced to give it up in Avengers: Infinity War, and its destruction in Avengers: Endgame leaves Dr. Strange without his more powerful weapon.
Plot details for pushed further to a March 2022 release, are still scant at the moment. As the film's title suggests, however, it will more likely see Doctor Strange traveling through the multiverse, exploring different realms as he fights a new, yet-to-be-named villain. With this, the sorcerer can easily come into with the Time Stone from a different reality, which he can use to defeat his latest foe.
Soul Stone in Guardians of the Galaxy Vol. 3
Technically not scheduled to be a Phase 4 film as it still has yet to nab a release date, Soul Stone in Vormir, it's possible that Gunn will incorporate the soul stone in the threequel's plot.
Or Guardians of the Galaxy Vol. 3 could deal with the version of Gamora alive in the main MCU timeline at the end of Avengers: Endgame. This 2014 version of the character has no recollection of her teammates or her love affair with Star-Lord. How Gamora will regain her memories of the years after she ed the Guardians remains to be a big mystery, but it's safe to say that it will be one of the main goals of the cosmic gang. To be able to fully explain what happened to her, it's important to retread the manner with which she died, including the fact that she was sacrificed for the Soul Stone, meaning that MCU fans haven't seen the last of the Infinity Stones.
