With Avengers: Infinity War hurtling ever closer and a huge question mark still hanging over the whereabouts of the last Infinity Stone, several rumours and theories have sprung forth trying to explain a connection in the MCU that will reveal its location. And a new theory has appeared that is surprisingly compelling and would tie Wakanda, Captain America and Tony Stark all together.
Step forward Reddit (once more) and user BigDabed to be specific, who has theorised that the mysterious element Tony Stark created in Iron Man 2 with the assistance of his father's hidden instructions was, in fact, a synthesised Vibranium.
According to that theory, Stark knew about the element on account of the small amount he had to make Cap's prototype shield. He would, in fact, have been intimately familiar with the material to be able to develop it into a shield, so he must have studied it at the most complex level. He simply didn't have the means to turn that knowledge into practical applications, so he stowed the information away until it could be used.
If that's the case, it would form a link between Wakanda and Iron Man, but also between the mysterious country and Captain America.
The theory suggests that Cap's super soldier serum - which Stark helped work on - was also developed using Vibranium. That can be the only way the serum has the same properties as the Wakandan Heart Shaped Herb: "increased speed, strength, and reaction time. Howard Stark probably used Vibranium in the serum, and this is why no one else has successfully able to replicate it, since Stark was the only one with access to it."
And further, the theory states that Stark's secret element is a version of Vibranium, which explains why Stark is resistent to the Mind Stone's powers when Loki attempts to control him in The Avengers. The element could be the only thing capable of resisting that sort of power as well as a blow from Mjolnir.
It also explains how Thor can supercharge Stark's arc reactor in The Avengers:
"Normal batteries can't just magically hold 400% power capacity. The only element we've seen that can convert being struck into energy is vibranium (as seen in Black Panther). Stark is able to absorb Thor's lightning and redirect it right back at him."
That all fits, and it's the kind of wide-spanning idea that would point back to an Infinity Stone being behind Vibranium (and by extension, Stark's element). And having the same power behind three characters as prominent as Iron Man, Captain America (and Bucky) and Black Panther would be a great way to add more importance to Soul Stone.
It definitely feels like Vibranium will be the key to the Soul Stone's mystery, and having this added link between the characters would be a very smart way to close the MCU up even more. And given the fact that we'll see Iron Man and Black Panther operating closely together in Infinity War, it makes sense that that's where we'll see the secret of the element revealed, both in terms of it being Stark's reactor source AND a link to the Soul Stone.