Since Vision was caught off-guard, he didn't have time to phase through the blade, and his synthezoid body began to malfunction. After Corvus Glaive's attack, Vision couldn't use his powers and remained badly wounded for the rest of the movie, which gave Thanos and the Black Order more freedom to confront the Avengers.
In theory, Vision should be one of the most powerful Avengers: He had the literal Mind Stone embedded in his forehead. But it's clear that Vision never tapped into the stone's true power — possibly because he knew what kind of destruction and horror that could cause.
Vision is killed by Thanos when he removes the Mind Stone to complete the Infinity Gauntlet in order to initiate the Blip. Years later, Vision's body is reactivated via Wanda's magic, albeit initially without his memories and with a different appearance.
Vision's Decreased MCU Power Level Improves The Story
Vision's powers have decreased as the MCU has progressed to prevent him from becoming a deus ex machina and overpowering other important characters' narratives.
Thor essentially 'gives birth' to Vision, which means there's part of him – or more specifically part of Mjölnir – in Vision, which gives him the ability.
Marvel FINALLY Reveals Why Scarlet Witch and Vision LOST So Easily - AVENGERS INFINITY WAR
Who is the most powerful Avenger?
Scarlet Witch
Doctor Strange in the Multiverse of Madness showcased Wanda's immense potential for limitless powers. She is undoubtedly the strongest Avenger in the MCU.
Thor's hammer Mjolnir was defined by the fact that only the 'worthy' could lift it – so basically no-one except the god of thunder (and Vision, for some reason). But when it comes to the weapon's replacement, Stormbreaker – which Thor forges in Avengers: Infinity War – Groot is able to lift it too.
Still, White Vision is the product of SWORD's attempts to rebuild Vision and use his body as a mindless weapon. Without the Mind Stone's power and without Ultron, Tony Stark, Bruce Banner, and Helen Cho's input, White Vision may never be the same, and he likely won't ever be as powerful as the original.
It can absorb and block energy attacks as well as penetrate vibranium—which Corvus does when he stabs Vision, twice, in the chest. Though neither blow kills Vision, the subsequent wound severely incapacitates the living android, taking away his ability to phase or recover easily.
Scarlet Witch Wasn't At Full Power Until She Learned From The Darkhold. Both Infinity War and Endgame hinted at how powerful Wanda was and could still be. However, neither of those films, as well as none of Wanda's previous MCU appearances, had come close to showcasing Scarlet Witch's true power.
He died twice for real in Avengers: Infinity War, twice as a magical creation in WandaVision, and once in Marvel's What If...?, but nobody stays dead in the MCU. Another version of Vision will return in Marvel Studios' Disney+ series Vision Quest, which has been officially confirmed (via Deadline).
The episode's post-credits scene also revealed the fate of real Vision's body, and it's not good: Hayward used some of Wanda's magic from the retro drone that SWORD sent in, and has completely revived Vision's body. Except now he's got a white tint, and will probably be used as an evil weapon.
Thanks to his artificial intelligence, Vibranium-infused synthetic body and the Mind Stone implanted in his forehead, Vision boasts an incredible number of unique powers.
In the Marvel Cinematic Universe (MCU), the title of “weakest Avenger” is subjective and can vary based on individual perspectives. However, if we consider powers and abilities, Hawkeye (Clint Barton) often stands out as the least superpowered Avenger.
In the strength class, I'd say Hulk outlasts Vision by far. Vision hasn't shown any massive strength feats, while Hulk stopped a Chitauri ship with one punch. Vision has the advantage in abilities and durability, mainly.
Captain America was simply an obstacle, and Thanos removed him. Otherwise, it doesn't look like Thanos had anything special against Captain America. In Infinity War, he just tossed him aside, albeit with a little respect after how hard Cap strained to stop Thanos.
This alternate has an argument, and perhaps the Thanos of its universe was somehow inherently weaker than the core MCU's, but there doesn't seem to be any scenario where the Sacred Timeline's Vision could ever defeat its Thanos, who had already harnessed five of the six Infinity Stones.
In infinity war, Corvus was able to: Best Captain America in a close range fight. Swiftly beat Vision (weakened vision to be fair, but still stronger than Okoye who EASILY put Glaive down in endgame)
While Vision's strength is only matched or superseded by a few characters, there's no doubt The God of Thunder would be one of them, and he's probably the strongest male Avenger in the MCU.
The Vision is quite strong as well - he can rip straight through a mutant-hunting Sentinel's armor - but not nearly as strong as Thor. The Vision's only hope in winning this battle rests with his unique ability to control his body's density.
Vision. Mostly, Vision is pretty much a direct copy of Superman, as he is able to fly, shoot lasers, and have super-strength. Superman could quite easily beat Vision with just these three abilities. However, Vision has the ability to phase through objects, something Superman doesn't have.
Mjolnir is a hammer, and was enchanted by Thor's father, Odin, so that only those the hammer deemed "worthy" are capable of wielding or even lifting it. Stormbreaker is an axe, and although it does not have such a worthiness enchantment, its power is such that a mere mortal attempting to wield it would be driven mad.
Stormbreaker can be used by anyone, it isn't bound by Odin's enchantments to only be lifted by the worthy. Mjolnir is, however, still enchanted, meaning that only those that are worthy may wield it. This applies to your last two questions as well. If you can lift Mjolnir, you can wield it.
During a Vudu Viewing Party for Avengers: Infinity War, co-directors Anthony and Joe Russo revealed a key difference between Thor's hammer Mjolnir and his new ax Stormbreaker: the latter doesn't require worthiness. That's why Groot was able to lift the ax, not because he was worthy but because he didn't need to be.
