Fans were shocked to see Ultron appear within Marvel’s animated What If…? Series, but even more so to see him wielding the Infinity Stones. During the most recent episode, we saw Ultron do battle with the Watcher using their power.
This has sparked discussion amongst Marvel fans who believe this either to be a plot hole or breaking news on how the Infinity Stones function within the MCU. For the longest time, fans have believed that the Infinity Stones only retain their power in the universe they are birthed within. This is due to that being alluded to in the comics and Loki seemingly confirmed this theory as the stones are said to be redundant during the series.
According to one fan who took to Reddit to share their theory, this might not be entirely true and the latest episode of What If…? May have intentionally revealed that they do have power in other universes, and instead it was the TVA that was blocking their strength.
What If…? Is part of the MCU canon so for the stones to be wielded between universes it likely confirms this theory to be true, especially given as the author of the post points out, it has yet to be said otherwise inside the MCU.
If this theory is to be true it isn’t clear what that would mean for the future of the MCU and if we could potentially see the Infinity Stones make a resurgence in a later phase of the MCU within a different universe.
