WARNING: The following contains spoilers for What If...? Season 1, Episode 8, "What If... Ultron Won,?" streaming now on Disney+.

It’s a testament to the staggering success of the Marvel Cinematic Universe that a figure as comparatively obscure as Uatu The Watcher could suddenly find himself front and center. As the franchise has grown, Kevin Feige and his team have reached deep into the lexicon to bring new characters into the mix. The Watchers have appeared before, as a very funny joke in Guardians of the Galaxy Vol. 2, which sees a trio of them listen to the late Stan Lee recount his travails in the MCU. But What If…? has brought Uatu to the forefront, exposing both his strengths and his weaknesses in the bargain.

As detailed in Tales of Suspense #53, The Watchers were a highly advanced race – the first civilization in the universe – who once inadvertently destroyed a less developed species by trying to help them. In response, they swore to never interfere in the goings on of the rest of the galaxy. Uatu struggles to keep that promise, and has broken it more than once. Among his more notable breaches was providing the Fantastic Four with the Ultimate Nullifier to stop Galactus in Fantastic Four #50. What If…? Season 1, Episode 8, “What If… Ultron Won?” forces him into similar circumstances, with disastrous results.

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Initially, the universe he visits in “Ultron Won” differs little from any of the series’ grimmer episodes. In it, Ultron successfully transfers his consciousness into the Vision’s body and becomes unstoppable. Thanos arrives to collect the Mind Stone and is slain within seconds, giving the AI the remainder of the Infinity Stones and the power to act as his own god. He promptly proceeds to exterminate all life in the universe – save Hawkeye and Black Widow, who desperately seek a means of stopping him in the drone-infested ruins of Earth – then suffers a terrible moment of existentialism when he realizes he no longer has a purpose.

Then, in a moment that shatters the fourth wall, Ultron becomes aware that Uatu is narrating his story in real time and turns to confront him. It’s not the first time it’s happened – Strange Supreme spotted the Watcher in Season 1, Episode 4, “What If… Doctor Strange Lost His Heart Instead of His Hands" – but in this case, Ultron has the ability to do more than interact. It’s a staggering realization for the Watcher, with his invulnerability breached for the first time. It also gives What If…? an opportunity to demonstrate how powerful he is, as well as where that power falls short.

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Ultron, to put it mildly, isn’t inclined to mince words. Destruction of the Multiverse provides at least a temporary escape from the crippling loss of purpose that affected him in his own universe, and Uatu appears to be the portal to that. With the power of the Infinity Stones, he breaks through the bounds of his universe, and launches a full-out attack on the Watcher. Considering the robot's nearly cosmic power at this stage, Uatu’s fears of Multiversal genocide are well founded. Yet he himself proves capable not only of resisting the staggering levels of damage Ultron inflicts, but fighting back as well.

But even as their battle takes them across the Multiverse and back, Ultron pinpoints his foe’s key weakness. “You lack the will to stop me,” he states succinctly, and he’s right. Throughout their fight, Uatu demonstrates higher levels of power, able to drive Ultron back and even encase him in energy spheres. And yet Ultron keeps pushing, and eventually drives him down. He’s forced to retreat and consult the dubious aid of Strange Supreme in order to stop his foe.

That comes down to will, as Ultron said, or more specifically to principle. Having taken an oath of noninterference, Uatu is slow to act when the Multiverse is in peril, and all of his cosmic powers mean very little in the balance of that. He cares about things greater than himself, such as the oath he took. Ultron cares only for himself, and that gives him the strength of purpose to overcome an ostensibly more powerful foe. The Watcher must break his oath to stop the menace, the surest sign of all that his philosophy can’t account for the threat he currently faces.

To see Ultron's rise to power, Episode 8 of What If...? is streaming now on Disney+.

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