They know Vecna is One (Henry Creel) because Eleven sees it during a psychic link (piggybacking) with Max, connecting the monstrous Vecna in the Upside Down with the orderly she banished, Henry, and also recognizes him as Subject 001 from her past at Hawkins National Lab. The Hawkins kids had already nicknamed the killer "Vecna" due to his D&D-like powers, and Will later recognizes the connection, linking the Upside Down's ruler to the original villain.
Max tries to provoke Vecna while her friends travel to the Upside Down to kill him. Eleven, aware of his return, enters Max's mind and confronts Vecna, who is revealed to be the mastermind behind the Upside Down's previous attacks on Hawkins, dating back to 1983 when Will Byers disappeared.
He used his restored powers to brutally murder the other test subjects and workers, and attempted to do the same to Eleven. However, Eleven overpowered him and sent him through a gate to the Upside Down, where he gradually transformed into the being known as Vecna.
In Stranger Things, Vecna is actually Henry Creel, also referred to as One (001). He is the son of Victor and Virginia Creel and acquired psychic abilities after a journey to Dimension X. He was subsequently used as a test subject by Dr. Martin Brenner.
Eleven is eavesdropping on that scene using her powers, even though the characters at Max's house didn't know it, so she learns that they nicknamed him Vecna and likely was the one to pass it on to Will, Mike, Jonathan and Argyle. That's why Will knows to call him that in the piggyback scene.
Before Vecna became the monstrous general of the Upside Down that fans are familiar with, he was a normal boy named Henry Creel (played as a child in the series by Raphael Luce).
Yes, in a way, the Demogorgon used Will Byers as a host to "impregnate" him with larvae from the Upside Down, as a part of the creature's reproductive cycle and the Mind Flayer's larger plan to spread its influence. A tendril was inserted down Will's throat, essentially planting a larva that would grow, leading to him coughing up slug-like creatures, but Will survived because Joyce and Hopper removed the tendril and the Mind Flayer's influence was later burned out.
Before they embark into the Upside Down, Will comes out as gay to his family and close friends, explaining that Vecna showed him visions of his failed and distant relationships with his loved ones after they learnt the truth.
Billy Hargrove and Max Mayfield from Stranger Things are step-siblings. Billy is Max's stepbrother, a relationship that came about when Billy's father, Neil Hargrove, married Max's mother, Susan Hargrove. This makes them a part of the same family, despite not being related by blood.
Vecna (Henry Creel) fears the cave because it's the site of his first, deeply traumatic exposure to the Upside Down, where he was accidentally teleported and first encountered the Mind Flayer, a moment that forever changed him and corrupted his humanity, despite his adult mind repressing it. The cave represents the origin of his powers and his loss of self, making it a place of terror and a mental prison he cannot enter, even in his own mindscape.
Eleven's "kryptonite" in Stranger Things Season 5 is a military-developed sonic weapon, often called the "Hedgehog," which emits a crippling, high-pitched frequency that overloads her psychic powers, causing intense pain and nosebleeds, possibly linked to the powers of Kali (Eight). This technology, developed by Dr. Kay, specifically targets psychics, effectively neutralizing them in ways her own emotional limitations or physical strain (like nosebleeds) couldn't, and it's the first time she's been completely shut down by an external force.
10 Most Heartbreaking 'Stranger Things' Deaths That Still Have Fans Crying—From Eleven to Eddie
Yes, according to the show's creators, Mike did realize that Will's "crush" in his coming-out speech referred to him, even though it wasn't explicitly stated in dialogue; his reaction shots and subsequent apology scene were designed to show he understood the depth of Will's feelings, though the payoff for their storyline was minimal in the finale.
Vecna targets Will Byers because Will shares deep psychic similarities, being a sensitive outsider, and became a crucial anchor or "phylactery" for Vecna's power after being connected to the Mind Flayer; Vecna sees Will as a vessel, a mirror of himself, and potentially a key to his immortality, needing him alive to maintain his own strength while also wanting to corrupt and use him.
The Upside Down was created on November 6, 1983, when Eleven made psychic contact with the Demogorgon. The Upside Down's origins are tied to the Abyss, an alternate dimension and the apparent home of the Mind Flayer entity, a race of humanoid predators and other lifeforms.
At his empire's height, Vecna was betrayed and destroyed by his most trusted lieutenant, a vampire called Kas the Bloody-Handed, using a magical sword that Vecna himself had crafted for him, now known as the Sword of Kas.
Billy Hargrove
Upon remarrying Susan and becoming step-siblings with Max, Neil forced Billy to address Max as his sister instead of step-sister. The abuse Neil endured on Billy resulted in his son secretly taking out his anger on Max.
Yes, Alice Creel is Vecna's (Henry Creel's) older sister in Stranger Things, whom he murdered with his powers when they were children, with her appearance being a parallel to Holly Wheeler, making her a significant figure in his twisted past. She was the daughter of Victor and Virginia Creel, and her death by Henry's hand was a pivotal event that led to his eventual transformation into Vecna.
Internationally, he is known for his roles as Jaqen H'Ghar in the second, fifth and sixth seasons of the TV series Game of Thrones, as well as Sebastian Berger in the TV series Crossing Lines. He also appeared in four episodes of Jack Ryan. He plays Dmitri Antonov / "Enzo" in the fourth season of Stranger Things.
The Duffer Brothers, confirm that in the coming-out scene, Mike realized he was Will Byers' crush. I liked this scene, Will putting his biggest fear — rejection of self — on the line before (most of) the people he cares about.
Billy's queer coding becomes more blatant during his interactions with Steve Harrington (Joe Keery), especially when they first share a scene in S2E2 (“Chapter Two: Trick or Treat, Freak”) at a Halloween party. At this party, Billy takes Steve's place as “Keg King” and does a stare off with Steve about it.
“He taps into the hive mind, and then he can manipulate anything within the hive. You'll see how far he can take it as you continue to watch. But that's how he's able to manipulate the monster.”
In Stranger Things, several characters say the F-word, including Will Byers, Billy Hargrove, and most notably, Joyce Byers (Winona Ryder) in a significant Season 4 moment when confronting Vecna, delivering a rare and impactful "You f***ed with the wrong family". Other instances come from characters like Billy (often possessed), and even faint or muffled uses have been noted from others like Jonathan.
Yes, Dart (D'Artagnan) is a baby Demogorgon, specifically an adolescent stage called a "Demodog," which Dustin Henderson found and raised in Stranger Things Season 2; he's essentially a younger, less aggressive version of the main monsters from Season 1, evolving from a pollywog-like creature into a four-legged, predatory form.
In the only cases of Demogorgon reproduction observed, the cycle began with the deposition of eggs or larvae within a host by a tendril within the Upside Down. The slug-like larvae were later vomited-up by the host, before subsequently escaping into the wild.