Character biography Vecna was born as a human, centuries ago as a member of the untouchable caste in the Flan city of Fleeth on Oerth. He was initially trained by his mother, Mazzel, in the art of magic, before she was executed by the government of Fleeth for practicing witchcraft.
In a fit of rage, Henry used his restored powers to brutally murder the other test subjects and workers, and attempted to do the same to Eleven. However, Eleven stood her ground and ultimately overpowered him, sending him through a gate to the Upside Down; there, he gradually transformed into the being known as Vecna.
In the final episode of Stranger Things 4 Volume 1, it's revealed that Vecna isn't native to the Upside Down, but was banished there by Eleven after he gruesomely massacred the Hawkins National Lab. Vecna was the original child studied by Dr. Brenner and the son of Victor Creel.
They found it in Vecna (Jamie Campbell Bower), a terrifying creature crafted by prosthetics and makeup designer Barrie Gower, who also worked on the Night King for “Game of Thrones.” Here, he takes us through the making of the Upside Down's newest (and scariest) nightmare.
Eleven has a memory during this episode and realizes that 001/Henry Creel (Jamie Campbell Bower) wants her to join him on his evil journey, and she banished him to the Upside Down. 001 then transformed into Vecna, the horrifying Stranger Things villain.
As Vecna continued to go after young victims in order to open more portals, he set his sights on Max Mayfield, since she was investigating the deaths of Chrissy and another student named Fred Benson with help from her friends (including Dustin, Steve, and her boyfriend Lucas).
Brown is likely right in saying that no one created the Upside Down and that the parallel dimension has always existed.
Vecna was inspired by mould
But according to Gower, they also “looked at a lot of sea life, moulds and animals to create the look, feel and consistency of his skin”. Gower says the Duffer Brothers were also “very adamant that Vecna be glossy and shiny, that he looked as moist and wet as the rest of the Upside Down”.
Next up, the viewers go on to theorise that One/Vecna is actually Eleven's dad. Yep, told you it was wild. The theory claims that Brenner wanted to create a child with stronger powers, so he waited until One was old enough to become a father.
The final scene of Volume 1 shows a shot of Vecna, and a close up of the 001 tattoo on his arm, confirming that Henry Creel, a.k.a. Number One, became Vecna.
Curiously, he also seems obsessed with time, projecting strange visions into his victims' minds—including of the grandfather clock from his home in the Creel House. Vecna's obsession with time appears to be linked to his hatred of 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.
Vecna hated humanity, believing human beings had imposed an artificial order upon the natural world.
Connecting to the Mind Flayer's hive mind allowed Henry Creel to become the version of Vecna that audiences see in Stranger Things season 4, controlling the Demobats, Demodogs, and Demogorgons across the Upside Down and the real world.
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.
He was initially trained by his mother, Mazzel, in the art of magic, before she was executed by the government of Fleeth for practicing witchcraft. Vowing revenge, Vecna eventually assumed a mastery of the dark arts achieved by no mortal before or since.
As the Duffer Brothers explained in an interview with Variety, the Massacre at Hawkins Lab was so traumatic for Eleven that she effectively blocked out all memories from 1979 and earlier. That's why her grammar was so limited again, and we saw in flashbacks that she had to be re-trained to use basic powers.
Vecna attacked Hawkins with the Mind Flayer. While it seemed as though the kids had defeated the creature's physical form at Starcourt Mall, they had lost without knowing it. Vecna used the attack to steal Eleven's powers.
Vecna is a dark mirror of Eleven herself, sharing all her powers, and potentially others as well. A series of flashbacks revealed Vecna was originally Henry Creel, a boy who grew up possessing strange psychic powers.
In the D&D realm, a defining feature of Vecna is that he's missing his left hand and left eye. 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.
Ultimately, it is revealed in Stranger Things season 4's finale that the reason why Vecna was killing Hawkins teenagers was to create a massive gate that merges the Right Side Up with the Upside Down - and he specifically needed four bodies to do so.
Vecna, unlike the other creatures, is a human who has mutated into a monster from overexposure to the Upside Down. He's been subjected to the toxic environment for around 20 years and has become a part of it.
He gets punished with electrocution after telling Eleven that Dr. Brenner lied to her about her mother dying during childbirth. He's smart enough to use an ostensibly harmless game of chess with Eleven to inform her Dr.
As well as befriending Eleven in order to gain her trust so she would remove his Soteria implant, we learn in the final episode that 001 initially spared El because he wanted her to join him. He viewed her as an ally rather than an enemy because they were "alike".
Then, as he was falling through the Upside Down, One became the creature Vecna after lightning struck him in such a way that it changed his skin and made him into the monster he is now. Stranger Things Season 4 Part 1 is out now on Netflix, and Part 2 will be released on Friday, July 1.