Vecna doesn't kill Nancy (Natalia Dyer), but he does leave her with a vision: a dark cloud, dead soldiers, and armies of monsters. This is Hawkins' future if Vecna (Jamie Campbell Bower) wins. He's dangerously close to winning, too, what with four being the magic number.
More than this, Vecna shows Nancy the fate of Hawkins and the world, making the dangers that will be unleashed in Stranger Things season 5 even more frightening.
And while his usual modus operandi is to embody his victims' negative self-talk (another very real psychological phenomenon), this time he is telling Nancy his plans and then releasing her so she can report back to everybody—Eleven included—that the end is nigh, with the goal of discouraging and disempowering them.
She narrowly evaded death each time, but it could eventually catch up to her. By targeting Nancy, Vecna would demonstrate that he's more frightening, intelligent and powerful than anyone initially assumed. She's easily the character who knows the most about him and understands fragments of how his mind works.
"Vecna seems to be actually intrigued by Nancy being able to figure him out, to be able to get this close to the truth... I think this is more Vecna's narcissistic traits that pull him to Nancy, why he wants to give her this information."
Stranger Things Star Millie Bobby Brown Cried the First Time She Saw Vecna. One of the side effects of using practical creature effects?
While intending to get his revenge on Eleven and Brenner, Vecna also goes after victims who have dealt with traumatizing experiences in the past (reminiscent of his childhood and his time at the Hawkins lab).
Brenner (Matthew Modine) states in the Stranger Things episode "Papa" that Vecna "consumes" everything about his victims, Vecna targets traumatized victims because it builds for him a well of sad and angry memories to draw from. With each victim, he can become gradually more powerful.
However, either she didn't have a great aim or she was trying to play it safe because she didn't hit him in the face even once, and that may be the reason why Vecna is still alive. Obviously, Nancy was trying to play it safe. She even cut off the muzzle of her shotgun so she could have the best odds.
Instead of escaping Vecna's Mind Lair by hearing her favorite song, Nancy is actually released by Vecna himself. Her freedom comes with a price: He gives her a vision of his plans for Hawkins and tells her to pass that message on to Eleven (Millie Bobby Brown).
The theory is that Karen Wheeler might be Vecna's sister, Alice Creel. As we know, Vecna is actually a man of many names, including 001, Peter Ballard and Henry Creel. We saw Henry and Alice together as children briefly in a flashback and it is believed that Henry killed his sister along with his mother.
What is the significance of 4 for Vecna? The new season shows that the four chimes of the grandfather clock symbolize the four victims Vecna needs to claim in order to enter our dimension and take over humanity.
It seems that the reason why Vecna wasn't killing for the seven years after the Hawkins Lab massacre was because he was waiting to become more powerful as the Mind Flayer and Demogorgons took more victims, as he was likely weakened after being thrown into the dimension.
When Nancy describes her visions, she talks about a creepy monster with a gaping mouth. It doesn't sound like one we've seen this one in the Upside Down before. So what is it? Our theory is that it is the Thessalhydra.
Fred Benson, a friend of Nancy's who was similar to Barb, was cursed and killed by Vecna. His death brought back Nancy's trauma, guilt, and grief over Barb's death.
However, Nancy is freed by Vecna within the first five minutes of volume 2, with instructions for her to tell Eleven what he has planned for Hawkins. Nancy wakes up to see Steve and is never affected by the curse again, despite Max Mayfield (Sadie Sink) escaping Vecna only to again be attacked by him later on.
(All of which have been cited by show creators the Duffer brothers as inspirations for the villain.) But he does have a surprising weakness: music.
He's a kid with a lot of emotions that he never learned how to express with words or say something as vulnerable as "I love you", and thus expresses his feelings with actions instead. The difference between Eleven and Mike is clear.
On March 24, 1986, Max Mayfield entered the mindscape while afflicted with Vecna's curse, but managed to break out of the hallucination and escape to reality. On March 26, Nancy Wheeler was pulled into the mindscape while trying to escape the Upside Down, and was terrorized by Vecna.
Clocks represent a passing of time, which can represent the fact that Vecna's victims' time has nearly run out — it is no coincidence that many of the clocks are set to midnight. Throughout the series, we learn that Vecna is a human who found himself trapped in the Upside Down for years thanks to our girl, Eleven.
In the visions of her trauma induced by Vecna, Chrissy's mother appeared both mentally and emotionally abusive towards her daughter - and it's implied her comments about Chrissy's figure caused her daughter to develop her eating disorder.
While falling into the dark dimension, One/Henry is struck by lightning, disfiguring him.
Though Fred appeared to be bright and level-headed, he harbored extreme guilt for his role in the fatal 1985 car accident, and believed many people look at him as a "murderer." This guilt and mental unrest made him a target of Vecna.
In the game, Vecna seeks power through artefacts, while in the series, he enhances his powers by consuming the essence of his victims, like the other gifted children in the lab, and absorbing their powers. When he took over the Mind Flayer, he gained control over the Demogorgons and other monsters.
Hawkins has suffered a lot of trauma over the years - not all of which is connected to Hawkins Lab and the Upside Down - and Vecna's curse takes advantage of that. Vecna appears to carefully choose people who feel a strong sense of guilt or shame, particularly if those emotions are repressed.