Wanda was only interested in getting her kids back, but they were never with
While watching Multiverse of Madness it was impossible not to wonder why Vision barely merited a single mention in the film, let alone Wanda's complete indifference to his existence. The grief from losing Vision drove her to imprison a whole town of innocent people in Westview in WandaVision.
Despite all their ups and downs, the odd couple that is Scarlet Witch and Vision tried their best to make their unique lives work. And, while things didn't work out romantically in the end, the two have now found friendship.
As to why Wanda didn't search for Vision in Multiverse of Madness, it could simply be that the android is dead in every universe. Wanda could have already searched the multiverse for a universe where she had everything she wanted, a universe with the love of her life and her two children.
Because the Vision inside the Hex doesn't actually exist. That Vision was basically a mental projection that Wanda created using her reality warping abilities. Just like how the entire town inside of the Hex was "created" by here.
The Russo brothers, who directed Infinity War and Endgame, once said that Wanda intentionally dropped the accent because she was training to be a spy and the accent would give her away.
In the comics, while White Vision cannot feel love for Wanda, he always respects their relationship as man and wife.
Wanda did not bring Vision to life
But as far as bringing back the dead is concerned, she has confirmed that she can't revive someone who is dead.
As for why he isn't in Multiverse of Madness, not all the Avengers are always present for calamity. Vision could be out in the world trying to fully regain who he once was, assuming he hasn't already. He could even be grappling with the multiversal chaos in his own way.
White Vision only has memories of the films, leading up to and ending with his death in Avengers: Infinity War. However, these memories were enough to snap him out of Hayward's control. He no longer sees Wanda as an enemy and he rejects the mission to be a sentient weapon.
But Vision and Wanda stand there and Wanda grips Vision's face the way people onscreen do when things are very intense, and Vision says, “We have said goodbye before, so it stands to reason—” … “we'll say hello again,” Wanda finishes.
Meet the happy family. In the comics, Wanda and Vision get pregnant through magic — since Vision is a robot, that's seemingly their only option. They have twins named Thomas and William.
But Thanos still had other plans. He used the Time Stone to turn the clock back, and plucked the stone out of a once-again-alive Vision's head, killing him for a second time. Thanos snapped half of the world out of existence, Scarlet Witch one of the many heroes erased.
Later in the memory, after Vision is killed, Wanda drives to Westview where, apparently, Vision had purchased a plot of land where they could build a house and “grow old together.” (Can Vision grow old?) Wanda is so overcome with grief that magic just bursts right out of her and creates the Hex.
Because she knows it wouldn't be real. Even if she could recreate he kids and Vision outside of a Hex she would know it wouldn't be real.
Wanda's eyes turning red is a manifestation of when she is using her power of reality warping. Her eyes turning red is a character trait that has been held by powerful magic users in the Marvel universe, so it's a sign of her strength and control over her gifts.
It represents the wisdom of the sorcerer Agamotto and his fellow Vishanti, allowing Strange to see his enemies' true intentions and break magical illusions. Doctor Strange's third eye is originally a sign of a higher level of consciousness, and it can only be used by those whose souls are devoid of corruption.
When Wanda finally pulled down the Hex, it erased him, and the twins, and the house that they lives in, from existence. And the White Vision, built from Vision's destroyed body by Hayward and S.W.O.R.D., is still alive and well.
The return of White Vision after WandaVision
For the moment, the series is known as Vision Quest and will introduce us to the White Vision in his mission to recover his human side and his memories after the final events of WandaVision, in which this new Vision escaped from Westview with his new appearance and identity.
Scarlet Power
As her powers likely come at least in part from the Mind Stone inside of Loki's scepter, Wanda's abilities include telekinesis, energy manipulation, and some form of neuroelectric interfacing that allows her to both read thoughts and also give her targets waking nightmares.
Infinity Stone > Mjölnir
The strongest, most logical theory why Vision can lift it with relative easy is due to the fact he is created with an Infinity Stone – the one found within the gem of Loki's scepter.
We see her during an experimentation where she's locked in a room with the scepter, which houses the Mind Stone. She's told to touch it, even though we hear a scientist say that not one subject has survived direct contact.
She can't have her happy ending by being the Scarlet Witch. The Witch was prophesised to rule worlds, not raise a family. Had she succeeded and stolen her sons from another universe, they would have been, for all intents and purposes, captives.
The Vision's body could be rebuilt, but his consciousness had effectively died. While dismantling him, the agents damaged his skin in such a way that it could no longer keep his usual color scheme, and turned stark white.
Director Sam Raimi and writer Michael Waldron, as well as Marvel apologists, argue that Wanda is victim to stages of grief, which amounts to an incongruent Scarlet Witch committing mass murder and regresses Wanda to a manipulative archetype desperate to be a mother again.