Patrick was born sometime between 1967 and 1968. Patrick's father subjected him to verbal abuse, and likely also physically abused him; he was berated and called "an embarrassment to [his] family" when discovered to be drinking alcohol, and on another occasion, appeared at school with a black-eye.
Vecna's '86 victims include Chrissy Cunningham (Grace Van Dien), who suffered from her mother's body-shaming abuse. School newspaper reporter Fred Benson (Logan Riley Bruner) fled from a deadly car accident that continues to haunt him. Patrick was targeted due to his father's abuse of him.
Vecna, an evil spellcaster named after the Dungeons & Dragons character, is killing and feeding off the trauma of his victims in order to emerge from the Upside Down into the real world at full power.
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 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).
Once he takes control of the mind, he traumatizes them by showing the visions of their dark past. He takes them to unknown places and gives them a glimpse of himself. The pain of his victims doesn't end here. Every single one of his victims experiences nose bleeding and severe headaches as well.
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.
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.
Younger people probably make better dimension bridging devices/batteries and their suffering last longer. Vecna needs those gates to destabilize the barrier between dimensions. I don't think he's particularly interested in finding Eleven until he knows she's alive. For all he knows Eleven is dead.
This is because his trusted accomplice, Kas the Bloody-Handed, betrayed him and used the sword Vecna created himself to chop off his left hand and remove his left eye. This ultimately destroyed Vecna. Though they're clouded with cataracts, Vecna in Stranger Things has both of his eyes. For now, at least.
Played by Jamie Campbell Bower, each prosthetic was glued to his skin with medical adhesive by prosthetics designer Barrie Gower and his team. For the finishing touch, Vecna was covered in "glossy slime to make him really, really glossy and wet looking," according to Gower.
"Vecna really is a creature that has mutated in the last however many couple of decades during his time in the Upside Down," prosthetics designer Barrie Gower said. "This is where he has become more overtaken by the Upside Down world and become pretty much possessed and mutated."
Vecna's first season 4 victim is Chrissy Cunningham (Grace Van Dien), who is targeted based on the trauma she carries due to her body-shaming mother.
The Hawkins kids manage to save Max - interrupting a vision that began with her guilt and shame over the death of her step-brother Billy in season 3 - by playing her favorite tune. They rightly deduce that music connects with the brain on a deep level, disrupting Vecna's hold and providing a way of escape.
It's probably safer to say that Billy was chosen as the Mind Flayer's first victim because of his fragile state of mind. He was constantly angry, overwhelmed by his abusive father, and became abusive himself in return.
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.
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.
The theory predicts that Vecna wants to regain his human form, and he will use Will to do so in Season 5. Knowing that Vecna singled out Will in Season 1, it's a reasonable theory, but it might go too far. After all, Vecna already has a human form, and he has vowed to eliminate humanity.
Vecna's Hand
This is a reference to the D&D character Vecna, for whom this Vecna is named; the D&D Vecna has a monstrous hand infused with dark magic. The design of Vecna's hand is also a nod to Freddy Krueger, the Nightmare on Elm Street villain who had a huge influence on this season in general.
The Hand and Eye of Vecna were all that remained of the arch-lich Vecna after his betrayal at the hands of his trusted vampire lieutanant, Kas the Bloody-Handed. Using a sword crafted by Vecna himself, Kas manage to cut off Vecna's left hand and left eye before in turn being destroyed.
"The reason why Vecna only has a single eye and hand is due to a betrayal by Kas", who used the sword against his former master. "In the third edition of Dungeons & Dragons, the Sword of Kas is a +6 unholy keen vorpal longsword that grants a +10 modifier to the Strength score of its wielder".
Vecna adopts psychological warfare to target his prey – which, you could argue, very much serves as an allegory for trauma, depression and mental illness, which is all too real.
(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.
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.