Marvel's latest hit show What If...? has confirmed once and for all exactly why The Avengers really are the most powerful heroes in the MCU. Ironically, this elevated status doesn't necessarily come from extraordinary abilities or physical prowess – although those, clearly, are also in ready supply. Instead, the supergroup's definitive ranking is actually down to something much more intangible that ultimately causes their opponents to underestimate them time and time again.

Throughout the MCU, Earth's mightiest heroes have developed a happy habit of overcoming overwhelming odds in almost impossible circumstances. Whether it's repelling an invading Chitauri army as a team during the events of the very first Avengers film, or acting alone during their various solo projects, the six original superheroes have, without a doubt, an impressive track record. Ultimately, as seen during the climax of the Infinity Saga, the crew is even capable of defeating an intergalactic titan capable of wiping out half of existence.

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Given the long list of enemies who have fallen foul of The Avengers, their reputation is clearly well-earned. However, for all their firepower, What If...? makes it clear that the real key to The Avengers success actually lies in their humanity. As Jeffrey Wright's omniscient Watcher explains while watching Clint Barton and Natasha Romanov search for the key to defeating Ultron, "You’re human you keep hope against the best of odds." This highlights a consistent theme running throughout the MCU – that it is the optimism, determination and refusal to be beaten that defines humanity that ultimately makes The Avengers such a dangerous prospect for Earth's would-be conquerors.

Black Widow What If

This argument is evident as far back as Phase 1 of the MCU, and is most obviously on display during the first Avengers movie. For example, Tony Stark's iconic "you can be damn sure we'll avenge it" quip to Loki is far more than a call-back to the movie's title – it also highlights his indomitable spirit, flying in the face of Loki's belief that humans are "made to be ruled". Similarly, one of the movie's most powerful moments comes when an old man stands up to Loki in the face of imminent destruction. This serves as a reminder that, even without any superpowers, humanity is capable of extraordinary bravery. It is this quality that ultimately makes The Avengers capable of their most extraordinary feats.

In many ways, the plot of What If...? episode 8 really emphasizes the point that humanity is the greatest power in the MCU. It is extremely telling that, in the aftermath of Ultron's assault, it is Barton and Romanov – on paper the team's most under-powered human characters – that are the last two left standing. It is their human spirit, shared with the likes of Stark, Steve Rogers and Bruce Banner that allows them to unlock the key to saving the universe. Although the MCU is inhabited with innumerable fantastically powered superbeings, time and time again it is those who have a close connection to humanity who emerge victorious.

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