There's no way around it: the Marvel Cinematic Universe is doomed, and many heroes will try to rise to the occasion and fight for the fate of the multiverse. Unfortunately, not even the combined might of the Avengers, the X-Men, Thunderbolts, and Fantastic Four could be enough to save the day.
The very first trailer for Avengers: Doomsday features a scene where Thor swings his ever-trusty axe, Stormbreaker, against Doom with all his strength. However, the ruler of Latveria stops the blow with two fingers alone. It's clear that the God of Thunder was aiming for the head, but while this tactic proved effective against Thanos before, the MCU's newest villain won't be so easily defeated.
To make things more complicated, leaked Avengers: Doomsday pictures reveal that Doctor Doom will have an entire coven of witches by his side, who will likely support him in his mission to bring the multiverse together under his reign. All hope seems lost from the get-go, and if Earth's Mightiest Heroes want to win, they are going to need a miracle. Fortunately, it seems one of the MCU's newly introduced characters could singlehandedly turn the tide for the good guys (and no, we're not talking about Namor).

A toy description reveals Shang-Chi may be the only hero strong enough to stop Doctor Doom in Avengers: Doomsday
Hasbro has unveiled its Marvel Legends Shang-Chi figure for Avengers: Doomsday, and its description suggests that only the power of the Ten Rings will be strong enough to stand against Doctor Doom:
"With the powerful Ten Rings around his arms, Shang-Chi may be the only hero powerful enough to stop the threat the Avengers face."
Toy leaks and descriptions are infamous for painting a very accurate picture of the events set to unfold in an upcoming movie, so it's all but a given that Shang-Chi will be one of Marvel's last hopes. So far, the true origin of the Ten Rings remains a mystery in the MCU, with Captain Marvel and Bruce Banner revealing that they are more than a thousand years old and that they are sending a signal, although nobody knows where.
There is a chance that the past of the Ten Rings is finally explored in depth during Avengers: Doomsday, unveiling why they are the only weapon strong enough to challenge Doctor Doom and his coven of witches. Granted, other heroes could also be a match for the Ruler of Latveria on paper, but not all of them will be on the right side of history.
It has been reported that one of Doom's followers, called Boris, will turn out to be Doctor Strange himself. We know Stephen is a very pragmatic person who could really support Doom if the villain has a plan to save the multiverse as a whole, even if it costs some lives in the process. A similar scenario also seems to be in store for Scarlet Witch, who is rumored to be on the villain's side as well.
While Bob could also go toe-to-toe with the ruler of Latveria as Sentry, a sudden transformation into the Void is all that's needed to make him more of a problem than a solution. Captain Marvel and Hulk are also ideal candidates to fight Doctor Doom, but they aren't set to appear in Avengers: Doomsday for the time being. As such, all eyes are set on Shang-Chi, whose Ten Rings of unknown origins could prove to be Earth's last hope.
That being said, it is likely that Shang-Chi's participation in Avengers: Doomsday won't be enough to stop the Ruler of Latveria. After all, Avengers: Secret Wars is on the horizon, and it won't be until then that we'll see a resolution to all the multiversal madness that has been unfolding.
Avengers: Doomsday will be released on Dec. 18, 2026.
