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.
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.
Vecna's holy symbol is an eye in the palm of a left hand. Vecna's "right-hand man", who ultimately became his betrayer, is Kas the Bloody-Handed, a vampire whose sword, the Sword of Kas, is also an artifact.
If Vecna can overwhelm their victim with fear, and keep them from resisting, their fate is almost certainly sealed. In the real world, he makes the victim levitate while in their trance, before snapping their bones and neck, and crushing their eyes.
The Eye of Vecna was a powerful and evil artifact that granted its wearer supernatural senses and access to powerful spells.
Essentially, Vecna hates humanity, and wants to take over their world. He had hoped that Eleven would help him achieve this goal. But when he realised she wouldn't, Vecna instead used her.
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.
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).
Vecna's obsession with time appears to be linked to his hatred of humanity. He views time as a human imposition on the natural world; an attempt to impose order on nature.
She opened a portal to the Upside Down, which sucked Henry Creel in. There the dark mirror world ripped apart his skin as it began to remake him into something sinister and twisted. But it was a transformation Henry Creel welcomed.
The final shot shows One/Henry in his present form—Vecna—with a tattoo reading 001 on his wrist. Vecna is One, who is Henry Creel. One, previously known as Henry Creel, ultimately became Vecna after Eleven defeated him at Hawkins Lab.
All those years ago, he felt a connection to Eleven because of their shared abilities and the pain that they had both endured at the hands of Dr. Brenner. But much to his disappointment, Eleven rejected him and his visions for the future.
The first reason that Vecna was stronger than Eleven is simple. He was older and more experienced. He was the original subject in Project MKUltra, and using his DNA, Dr. Brenner was able to make or alter the other children so that they would also have powers.
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.
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. Krueger had a glove with razors attached to it like long claws; he wore it on his right hand, though.
Realizing he had tremendous psychic power, he haunted his family with visions before ultimately killing most of them. His father was framed for the murders and locked away in a mental hospital as a disturbed serial killer. Henry then found himself in the care of Brenner, who decided he wanted more kids like the boy.
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 draws power from sad and angry memories and that is the main reason he targets traumatized teens. Those teens are a well of power just there to be absorbed. This is not just a theory, Vecna himself told Eleven about the power that angry and sad memories hold. Also in episode 8 of Season 4 named “Papa,” Dr.
Before coming to the Hawkins National Lab, Venca had a classic villain origin story — he became obsessed with black widows, tortured his family, and brutally killed his mother and sister pinning it on his father.
As Vecna, he uses these mental abilities as a way to psychologically weaken and lure in his victims – much in a way that Pennywise, Freddie Kruger, and Pinhead do. (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.
When One massacres the rest of the children in Hawkins Lab, Eleven banishes him to the Upside Down in the same way she banishes the Demogorgon from season one. One is sent hurtling through the Mind Flayer's lightning and is horribly disfigured, transforming into Vecna.
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.
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.
Based on the flashback in “The Hellfire Club”, he killed an estimated 21 people: 13 lab subjects, two orderlies, two guards, Ten, Alec, Dr. Ellis, and Six. A flashback during “The Massacre at Hawkins Lab” later reveals that Vecna killed even more people in Hawkins Lab than we thought.
Orcus, the demon prince of undeath, taught Vecna a ritual that would allow him to live on as a lich. Beyond death, he became the first and greatest of all liches.