It could be that SWORD was secretly planning to rebuild Vision (Paul Bettany) without the Mind Stone in WandaVision. Though it wasn’t associated with him in the comic books, the Mind Stone was the most important component in the body of the MCU’s Vision.
Years ago, the Infinity Stone that powered Loki’s scepter was placed in Vision’s head by Ultron, thus allowing the snythezoid to have a power img. Because of the Mind Stone, he was able to operate as a member of the Avengers and engage in romantic relationship with Scarlet Witch (Elizabeth Olsen). In Avengers: Infinity War, his life was threatened by Thanos’ ruthless pursuit of the six Infinity Stones. The Avengers worked to protect Vision from harm, but in the end all their efforts were in vain. Once the Stone was ripped from his body by the Mad Titan, Vision was no more.
That being said, Vision is somehow alive again in WandaVision. It appears that he’s been resurrected somehow, but he can only live inside the Westview barrier. Monica Rambeau (Teyonah Parris), Jimmy Woo (Randall Park) and Darcy Lewis (Kat Dennings) don’t understand how Wanda pulled it off yet, but it could be that characters within SWORD have had their own experience with rebuilding Vision. The Mind Stone being destroyed offscreen by Thanos should have made that impossible, but it could be that SWORD was trying to see if Vision could live in some way without it. Here’s how that might have worked, how it would have connected to the comics, and what it would mean if they ever succeed.
The circumstances behind what happened to Vision’s body before WandaVision are suspicious. SWORD acting director Tyler Hayward (Josh Stamberg) explained earlier that Vision’s corpse was being kept in one of their facilities when Scarlet Witch came for it and took it away. Now, the character has been restored by some mysterious means. According to Hayward, this was against Vision’s own wishes. The will he left expressed a desire for his body to be left alone, and the implication was that Scarlet Wish violated that. However, it may be that it was actually Wanda who was trying to prevent Vision’s corpse being tampered with.
It hasn’t been confirmed that SWORD had designs on Vision’s body, but Hayward having an interest in him would make sense. After all, Hayward’s own words about SWORD’s new goals post-Avengers: Endgame perfectly illustrate what they could want from him. Hayward told Monica that they’re researching sentient weapons, and that’s a term that certainly fits Vision. There’s no telling what they could have gained from the technology within him, or what they could have accomplished. If it’s true that they were experimenting on Vision, that could be the real reason for Scarlet Witch’s attack. Upon finding out what they were up to, Wanda could have launched into a rage. Such a revelation would provide justification for Wanda’s conflict with SWORD and the level of hostility that she demonstrated toward them during the standoff outside the barrier.
There’s no telling what SWORD could have done with Vision’s body, as there are all sorts of different possibilities. For instance, they could have been working on a new android superhero like Machine Man from Marvel Comics. Or, it may be that instead of making something new, they simply wanted to make Vision live again (despite Hayward’s apparent opposition to it in a previous episode).
To understand how that could happen, it’s important to keep in mind that Marvel has found ways to bring Vision back when it seemed impossible before. The equivalent to the Mind Stone in Vision’s comic book origin were the brain patterns of the superhero called Wonder Man. After getting a hold of them, Ultron used them to make Vision a living and breathing person capable of reason and intelligent thought. When Vision was killed, Hank Pym struggled to rebuild him. What stood in the way of his plan was Wonder Man’s refusal to let his brain patterns get copied again. For this reason, they had to proceed with Vision’s reconstruction without them. As a result, Vision was ultimately restored, but he wasn’t the same. His appearance was now totally white and devoid of color. The loss of his red, green, and yellow color scheme reflected the fact that the character had lost the things that made him the Vision. Before his death, the snythezoid could experience emotions like any human, but the rebuilt version functioned on pure logic. His feelings for Scarlet Witch were gone.
If Vision’s Marvel Comics counterpart can live without Wonder Man’s brain patterns, it could be that the MCU Vision would be able to function without the Mind Stone. The problem though, is that there would likely be consequences to going down this route. The Mind Stone is so unique that it’s hard to imagine that SWORD’s technology – no matter how advanced it may be – can restore Vision back to the way he was. There’s a strong chance that if SWORD did make this work, he’d be the MCU interpretation of the colorless Vision from the 1980s comics.
Supposing SWORD did succeed in rebuilding the Vision without the Mind Stone, it seems plausible that he would just be an emotionless, highly-functioning AI in an android body. In a sense, he’d be quite similar to JARVIS before his evolution into Vision. A character like that could still be a valuable ally, especially if he was programmed to serve a good cause, but he wouldn’t be the Vision that Wanda loved, or the hero that fans know. Wanda could be aware of this fact, and that would be why she didn’t want SWORD to fix him. Without the Mind Stone, Vision wouldn’t be the person she knew, so she’d naturally be opposed to this course of action. To Wanda, the best alternative may have been to use her powers to recreate him just the way she remembered him, which was when he had the Mind Stone.
It’s worth wondering if SWORD could ever accomplish their original Vision plan (if resurrecting him really was their intention). That would of course depend on what ends up happening between them and Scarlet Witch in WandaVision. If they defeat her and require his body, The MCU could receive an all-new version of the iconic Avenger. That wouldn’t be the preferred solution to this storyline, but it may be the only way that Vision can exist for the time being. It may also just be a temporary situation, as it could be that a magical answer to the problem can be found in Doctor Strange in the Multiverse of Madness.