The Mind Flayer is one of the more dangerous villains that Stranger Things has introduced — save for Vecna in season 4. The evil entity, also referred to as the Shadow Monster, made its debut in the Netflix show's second season. After wreaking havoc on the citizens of Hawkins, it returned in Stranger Things season 3, albeit in a different form. The Mind Flayer harbored significant powers, and many of those abilities were on display when battling the show's plucky human heroes. As it turned out, season 1's Demogorgon was just one creature that resided in the Upside Down. Though it was a serious threat on its own, the species was actually controlled by the Vecna.
The supreme leader pulled the strings when it came to any living matter that came from the dark dimension. Unfortunately, it also held abilities that could affect those living outside the Upside Down — something that Will Byers learned quickly. Stranger Things season 4 saw the king of the Upside Down, Vecna, come to light as the series' titular Big Bad. The latest installment also helps put more of the Mind Flayer's powers into context, as it was revealed that Vecna was in control of the monster the whole time. While the Mind Flayer boasts some serious abilities, none of them would be possible without Vecna himself. Here are all the powers Stranger Things' Mind Flayer has explained.
Hive Mind
When the Mind Flayer was introduced in Stranger Things season 2, it presented one of the monster's most distinct abilities: the hive mind. As the ruler of the Upside Down, Vecna had full control over the creatures from the other dimension, including the Mind Flayer. Aside from the Demogorgon, Vecna was able to command the army of Demodogs to specific locations throughout Hawkins. When its connection with Will was made, the Mind Flayer had control over his mind, but on the flip side, he could hack into the monster to gain key insight into its weaknesses.
Human Possession
For the Mind Flayer's hive mind to work, the monster must infect an individual. In doing so, the victim would act as a host body for the Mind Flayer's possession. This occurred with both Will and Billy Hargrove, causing the characters to serve as spies in the primary dimension. By infecting and possessing other humans within Hawkins, the Mind Flayer was able to build a Flayed army. It was then able to control the army through the hive mind, making the monster even more dangerous. The only known way to stop the possession, and the hive mind, would be to burn the Mind Flayer's essence out with extreme heat.
Biokinesis
Before Eleven closed the Gate in season 2, a piece of the Mind Flayer that infected Will was left behind in Hawkins. When the new Gate was opened under Starcourt Mall, the Mind Flayer was able to control its remains from the other dimension to infect rats. Those rats then melted into biomass that formed together to create a proxy body. As the Mind Flayer took control of more humans, they too were melted and absorbed into the proxy form. The creature then evolved into the Hospital Monster and Spider Monster through biokinesis, before growing into its full form.
Power Absorption
In Stranger Things season 3, the Mind Flayer attacked Eleven and her friends at Hopper's cabin. Despite her own powers, Eleven was bitten by one of the monster's tentacles, leaving a piece of it embedded in her leg. The injury weakened Eleven's powers until they disappeared altogether. Even months after the group defeated the Shadow Monster, Eleven was still without her special abilities. Somehow, the Mind Flayer was able to absorb her powers after it bit her.
Atmospheric Control
Each time Will envisioned the Mind Flayer in Stranger Things season 2, the monster was surrounded by large stormclouds and red lightning. The same type of weather was shown when the Mind Flayer loomed over the middle school during the Snow Ball and when Eleven got an insight into Billy's childhood on the beach. The atmospheric control remained within the Upside Down, but the weather change seemed to have a connection to the Mind Flayer's emotions.
Vecna is Controlling the Mind Flayer
It came to light in Stranger Things season 4 that the Mind Flayer was actually formed from dust by the villain Vecna/Henry Creel/One. The powerful psychic is truly the one that has been controlling the Mind Flayer the entire time, meaning that he is the one who is capable of maintaining a hive mind, human possession, atmospheric control, biokinesis, and power absorption. The Mind Flayer is simply Vecna's puppet, doing as its master says and wishes. He created the creature out of a dark cloud of dust so that it would form the iconic betentacled form of the Mind Flayer that only he can control, transforming nondescript particles into a formidable foe with incomparable psychic abilities. Not only does he control the Mind Flayer, but he also controls every creature that has emerged from the Upside Down — making him Stranger Things' most powerful villain.
