The secret of the six stones could be finally revealed as Avengers: Infinity War hits the theaters in April.
A promo art teased that Robert Downey Jr.'s Iron Man might be keeping the Soul Stone from Thanos. The Soul Stone is the last missing piece, as the other five stones are in the possession of other Marvel heroes.
The Tesseract or the Space Stone was revealed in Captain America: The First Avenger, while the Orb or the Power Stone was seen in Guardians of the Galaxy. Fans also saw the Aether in Thor: The Dark World, and the Mind Stone was captured in Avengers: Age of Ultron. Dr. Strange has the possession of the Eye of Agamotto, which is also known as the Time Stone.
Finding The Soul Stone
Movie critics said that it is unlikely that Marvel has intended Tony Stark to keep the Soul Stone all along. Fans have speculated that the Soul Stone might be in either Thor: Ragnarok or Black Panther. However, Ryan Coogler, director of Black Panther, said it would be redundant for one show to have two magic gems to serve as Wakanda's source of power.
"I love the Infinity Stones as much as any comic book fan, it's just Wakanda already has its thing, which is Vibranium," Coogler said in an interview.
"For us, that was special enough, so to throw in something like another special thing didn't feel right. It felt like we should stick with our one MacGuffin for the country and explore that, let that be the important thing because, frankly we didn't need to have another piece like that," Coogler added.
If it happens that the Soul Stone is missing in Avengers: Infinity War, fans said the next possibility would be a blast-from-the-past style in Captain Marvel.
There are other versions surrounding the Soul Stone. Tony Stark's association with the last piece of the six stones is triggered by Howard Stark's message to his son in Iron Man 2. In that message, Howard told Tony that he is and will always be his greatest creation.
Theorists believe that the Soul Stone could have transformed into another life form, which is Tony Stark, similar to what happened to Aether and Tesseract.
However, fans will still have to decode the origin of the Soul Stone, whether it was buried deep on Earth, same with the Tesseract.
Avengers: Infinity War is slated to hit theaters starting April 27.