"My domain is the upside down and earth is a stepping stone for this. I created the upside down for eleven. I will not yet reveal my plans but I assure you, you will be stepped over. The Upside Down is an alternate dimension existing in parallel to the human world. Most, if not all, flora and fauna present in the dimension are linked together in a hive mind controlled by me, The Mind Flayer. I am a sentient entity that possesses intelligence equal or superior to that of a human. This sets me apart from the Demogorgons, They behave purely on animalistic when I am not exercising my control over them. Here are my abilities"
- Hive Mind: My most distinctive feature is the ability to take control and command of the creatures from the Upside Down and later Will. Upon having its feeding area burned, I sent multiple Demodogs to the tunnels in order to deal with the problem. I also had them try and stop Eleven from closing the Gate. The downside of this mental connection was that the burning of tendrils would affect the Demodogs and Will, and most likely the Mind Flayer itself. Will was also able to learn instinctive knowledge of its goals, the tunnels, and its weakness. Despite the hive mind's reach, when Eleven sealed the rift between worlds, the connection was severed and led to the death of its subjugates.
- Possession: By imbuing a portion of its essence on an affected subject (despite both me and Will being in separate worlds), I am able to link the infected to the rest of its army. An example of its power was how I tricked Will into sending numerous soldiers to their death by having Will tell them its weakness was within the feeding area in the tunnels. The possession can be severed by subjecting the infected to extreme heat, which burns the essence out of its body by making it uninhabitable due to a weakness to heat and light. However, when a host is under threat of being discovered or severed from the my possession, its influence can force the host to fight back; it gave Will inhuman levels of strength, allowing him to remove its restraints and throttle Joyce effortlessly with one hand while she attempted to free Will from the creature's possession. When I later possessed Billy Hargrove, I gave Billy enough strength to bust down the door of the sauna room I was trapped in, even temporarily resisting Eleven's telekinesis and throwing a barbell at her. The affected subjects also seem to take damage that would otherwise kill a human, such as eating chemicals. Billy, under the my control, was strong enough to survive getting thrown through a brick wall at a high speed, and even survive getting hit from the side by a car. One further aspect of possession is that I learn from the memories of those I posses, as proven by the controlling of Tom Holloway ,once possessed, to lie about the family of Doris Driscoll "threatening litigation" to Nancy and Jonathan, a very specific human terminology that I would not have learned anywhere in the Upside Down. This is particularly concerning if I am able to return to the world once again having learned about human vehicles and technical weaponry; despite their abilities all of its "troops" so far have been, strictly speaking, hand-to-hand fighters that travel on foot, which are two extreme tactical disadvantages against modern weaponry and vehicles.
- Flayed Impairment: Under the influence of me, Billy's body is shown to be unable to repair injuries that it has sustained. This is shown after the Sauna incident, where Billy's arm and face are abraised; these injuries remain throughout the rest of his role in the show. It is unknown if this applies to any other aspects of the body, or if this is the case with all of the my subjects, as it could explain why the Demogorgon/Demodogs have a sickly appearance.
- Biokinesis: Through sheer force of will I can melt host bodies and maintain a proxy body, and even create smaller monsters under my control that can later be re-absorbed into the main proxy body, though this ability appears to be fairly limited as the Flayed need to be in close range to my main proxy.
- Weather control: When Will Byers witnesses me in the Upside Down, the creature is often surrounded by a large storm consisting of red lighting and thick black clouds. While the nature of these storms is not entirely clear, it is possible that I am is responsible for their creation. The storm is possibly based on my emotions. as I am seen looming over Hawkins Middle School, seething with anger.
- Power negation: After biting her with one of my tentacles, my proxy left a piece of myself inside Eleven, severely weakening her telekinesis later that evening. Even three months after defeating my proxy. Eleven's powers were not back to full strength. How I gained this ability is unclear, but it is possible that the chemicals the Flayed ingested played a part.
- Bio technology: I have been proven to be very, very adept at genetic analysis and manipulation. When I was effectively defeated by Eleven at the first Gate, within the span of roughly one year I fully developed the concept for the proxy body, a brand-new being created from melted animals, humans and chemicals, specifically designed to combat Eleven. The entire Demogorgon species was likely either conquered and modified by the me long ago or my direct custom creation, with both possibilities involving extensive genetic manipulation and design. The extensive vine networks are the same.