In its very first film, the MCU offered up a tease for a major Iron Man villain, but the franchise has doomed itself to never deliver on its promise. Though it may now span over 100 hours of total viewing, the MCU began with a single film. 2008’s Iron Man started it all, introducing Robert Downey Jr.’s Tony Stark to the world and establishing the most successful movie franchise of all time.
Iron Man did more than just introduce its titular hero, though. It also quietly began laying the foundations for the franchise as it exists today, hinting at multiple developments for potential sequels. One of these comes early on, and would likely go over the head of more casual Marvel fans. When Stark is kidnapped by terrorists, a flag in the background identifies them as the Ten Rings.
In the comics, the Ten Rings are kind of a big deal, but not quite in the same way. As an organization, they didn’t exist prior to the MCU, but it was a clear reference to the Mandarin. Iron Man’s archenemy, the Mandarin’s source of power is ten cosmic rings. The Easter egg offered a small tease for the Mandarin in Iron Man, but the MCU now can’t ever deliver it in earnest.
Iron Man Featured A Ten Rings Tease – Then Killed Him Before He Faced Them

Infamously, Iron Man 3 introduced the Mandarin, only to swiftly reveal him as a fraud. It was implied that the villain didn’t really exist within the MCU – pretty disappointing, given the earlier tease. However, Shang-Chi and the Legend of the Ten Rings then changed that, introducing the real Mandarin.
Sadly, at this point in the franchise, Iron Man was already dead. Sacrificing himself at the end of Avengers: Endgame, Iron Man never even got to meet his greatest enemy. It’s undoubtedly one of the MCU’s biggest missed opportunities involving one of its most popular characters.
The idea that both Iron Man and the Mandarin exist within the same universe but never actually got to face off is more than disappointing – it’s practically insulting. It’s like introducing Batman and the Joker and then keeping them apart by permanently killing one off. Obviously, there was an issue of timing, and the MCU’s eventual fix for their earlier Mandarin mistake was certainly welcome, but that doesn’t make it any less frustrating. In essence, it feels like the Mandarin won by outliving Stark, which just feels all manner of wrong.