Dr. Brenner's children were granted powers by treating their mothers with psychedelic drugs during pregnancy. Henry Creel appears to be different, however; there's no evidence his mother ever experimented with LSD. Rather, his powers seem to be natural, developing around puberty.
Remember also that we have evidence that powers can be inherited -- El inherited her powers from Terri Ives, for example. So it stands to reason that Henry inherited his powers from one of his parents.
In her rage, Eleven looks to disintegrate One, but instead sends him through to the Upside Down, opening her first gate to that other dimension. One bursts into flames as he is struck by beams of crackling energy, and ultimately becomes Vecna.
From the moment that he is born, 001 is a strange and odd child, and he seems to have powers from the very beginning of his life. When he begins living at the Hawkins Lab and Dr. Martin Brenner (Matthew Modine) experiments on him, it's clear that he is different from the other children.
Stranger Things had already established that Eleven's powers and her powered “siblings” were all results of Project MKUltra by the CIA, which experimented on expectant mothers by injecting them with doses of LSD. Season 4 retcons this by establishing that the powers that the children had were the results of Dr.
While the source of Vecna's powers is never explained, there are some Stranger Things hints leading to the theory that Hawkins had a big part in awakening them. Vecna is revealed in season 4 to be the base cause behind all of Hawkins' unfortunate happenings for the past three years.
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.
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).
The Duffer Brothers had Vecna planned from the start, which is how they were able to tie his character into earlier seasons. Stranger Things revealed Vecna was also behind the Mind Flayer that appeared in season 2.
Millie Bobby Brown spoke about this in an interview with Variety in 2022. When the actress was asked if the Duffer Brothers explained that Eleven creates the Upside Down when she interacts with 001, she said, "They did tell me. She does. She opens the rift."
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.
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.
"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."
He was born with supernatural powers, and when he spotted a nest of Black Widows he found comfort. The following month, Henry grew to hate human civilization, most specifically its structure of time and evolution.
Vecna hated humanity, believing human beings had imposed an artificial order upon the natural world.
One Steals Eleven's Powers
Just as Henry could see into the minds of others, from the Upside Down Vecna can still see into people. The vines of the dark dimension, which have made their way to the real world, connect directly into his body.
If he couldn't physically leave the Upside Down, Vecna needed to use the Mind Flayer to attack Hawkins. He also needed to figure out how strong Eleven's power had gotten since their last face-off. Through Demogorgons and The Mind Flayer, Vecna began to slowly break down the barriers between the two worlds.
In episode 7, Vecna is revealed to be Henry Creel (played as a youngster by Raphael Luce), the son of Victor Creel (Robert Englund) and his wife Virginia (Tyner Rushing) shown in the 1950s flashbacks.
Will Became Connected to Vecna During His Kidnapping in the Upside Down. The assumption has always been that Will survived in the Upside Down on sheer dumb luck before being trapped in those creepy hive mind vines.
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.
(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.
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. Finally, Vecna targets Max for her trauma from witnessing Billy's death and uses Barb's (Shannon Purser) death as a way to use Nancy.
In his twisted mind, Vecna believes that he his helping the world by wiping out humans, as a "predator, but for good." When Vecna asks for El to join him, it's because he also sees her as a predator, "better" than humans. He offers her his path as a sort of freedom, as they reshaped the world in their image.
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.
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.