The true villain of Stranger Things isn’t Vecna, obviously. The Upside Down already existed when Henry fell into it, and he was initially terrified, thinking that he was dying. However, he was transformed into Vecna. Why? Presumably because he was already a super-powerful psychic dude, and he was psychotic, and he was willing to offer himself to the Master of this Realm (the big dust-smoke-cloud thingy that Henry discovers in the Upside Down and gives himself to). Thus, the Evil Demon Lord Dude saw in Henry the potential for a Champion, a weapon. (In other words, the same motivations that Dr. Brenner had….)
And remember, in the Star Wars trilogy, Darth Vader turns out to not actually be the true Bad Guy; the mastermind of the whole thing is the Emperor, who Darth Vader serves as his champion.
So who IS the Lord of this Realm, the creator of Vecna, the true Master of Puppets who has been pulling the strings the whole time?
Dustin! Another drum roll please….
I think the true Master of Puppets, is Lolth, the demonic Queen of Spiders. In D&D lore, Lolth rules over a nasty realm of the Abyss, the Demonweb Pits, and in these Pits, is served by a bunch of nasty minions (like, in Stranger Things, the Demogorgon, Demodogs and Demobats). Lolth obviously has a thing for spiders, and Henry, remember, has a thing for spiders. Finally, before Henry transforms, and while his family is still alive but getting tormented by the Evil Presence in their house, spider-illusions are a key way of inflicting this torment.
Plus, there is a specific segment in the Dear Billy episode of Stranger Things, when Victor Kreel tells Nancy and Robin his backstory; his younger self is shown walking up to the attic to look for the Evil that he says he can sense is “hiding, nesting, somewhere within the shadows of our home”. At that moment, the camera focuses on a single black widow spider, hanging upside down from a thread of spidersilk.
In D&D lore, as noted above, Lolth resides in the DemonWeb Pits, a gigantic dimension (or “plane”) of the Abyss (basically like Hell, although technically in D&D lore, the dimensions of Hell and the Abyss are entirely different; however, I doubt that’s important here). The Demonweb Pits are covered in a huge, sprawling network of spider-webbing; in Stranger Things, they use the nasty vines, but it’s not much of a stretch to imagine that the webbing of an actual Demon Lord would be more like tough, slimy vines than silky spider-webbing; also, as noted earlier, remember that the resemblance to actual D&D creatures is only superficial, and in Stranger Things they tend to be a lot nastier (aside from the Demogorgon, who is super-wimpy in Stranger Things compared to D&D).
Also, in Stranger Things, we are told that if the characters step on a single vine, Vecna will know. Kinda like how, if a fly touches a single strand of spiderweb, the spider will know. Here, it’s not technically Vecna who will know; it’s Lolth. But of course, what Lolth knows, she can easily transmit to Vecna.
There are other interesting parallels to Lolth aside from the obvious spider connection. For one, in D&D lore, there’s a storyline in which Lolth attempts to invade Oerth (i.e., Earth), through a small town, called Istivin. In Stranger Things, a “gate” (classic demon mythology, opening an interdimensional Gate to enter the world….) has been opened in Hawkins, a small town, so that “Vecna” (or, presumably, Lolth) can invade and take over the world.
This one’s a bit of a stretch, maybe, but Lolth also rules over the Drow, the Dark Elves, and transforms those who fail her, into Driders through an awful process of deforming them into people with spider-bodies, kind of like spider-centaurs. Lolth is also served by grotesque demonic creatures called Yochlol, which have gross, waxy bodies with slimy tentacles. If you put the idea of Driders and Yochlol together, and extrapolate a little in the spirit of Stranger Things’ depictions of D&D monsters, Vecna/Henry, with his deformed tentacle-body seems pretty reasonable as a Drider/Yochlol hybrid that Lolth transformed after he lost his battle with Eleven.
While we’re on the subject of Yochlol’s, it seems highly likely that the grotesque monster thingy from Season 3, is a yochlol. Like the Mind Flayer, it’s a bit of an extrapolation from the D&D monster, but, roughly speaking, similar enough. (It could also be just a creepy gross monster, perhaps inspired by Jubilex, another Demon Lord. Given that Stranger Things reduced the Demogorgon to a mere monster, they might have done the same with Jubilex. That would make sense too, but I think a yochlol is cooler, and fits the Lolth theory perfectly.)
Finally, Lolth’s personality is one of absolute, chaotic evil. She loves to toy with her victims, messing with their minds and driving them mad……which is the modus operandi of Vecna in Stranger Things, who most surely is emulating his Goddess, the true Master of Puppets.
The one thing that really doesn’t fit the Lolth theory, is the Upside Down’s vulnerability to fire. As far as I can remember, Lolth was actually resistant to fire. This makes me wonder…. Or, this could just be for practical purposes. After all, fire is pretty cool to film, and easy, because we do have technologies like flame throwers and molotov cocktails. So if they went with something else (cold? acid? lightning?), it would be much more of a stretch for the characters to get their hands on effective weapons. So, I’m guessing they deviated from the lore a bit, gave the Upside Down dudes a fire vulnerability, just to make filming more possible.
(Or, I’m totally wrong, and the actual monster-thingy in the Upside Down is just the Mind Flayer, which Henry/Vecna gave himself over to. This is what the Stranger Things lore currently wants us to believe. But I think Lolth is a way better story. This whole thing can’t simply be a Mind Flayer; that doesn’t fit with the mythology of opening gates and now, starting Hell on Earth. That’s Demon Lord action, and Lolth is by far the best candidate for that.)
(There are other, minor possibilities. There’s Jubilex, a formless slime Demon Lord; the dust cloud thingy that Vecna sees is formless, the Season 3 monster is all slimey goo, and the vines are slimey, so….mayyyyybe, but I think that is silly and pretty unsatisfying, and there’s way more clues pointing to Lolth. Also, Jubilex’s mind is so alien and incomprehensible, that nobody understands it, whereas the plot of Stranger Things is pretty standard Demon Lord fare — open a Gate, take over the world.
There’s also a different Demon Lord known as That Which Lurks. The main clues are that TWL, in D&D lore, specifically used mind-magic to persuade his worshippers to follow him (similar to Vecna), and TWL played a role in ultimately empowering Lolth. So, mayyyyyyyyyybe, Lolth, like Vecna is also a key minion of TWL, but I think this is highly unlikely, and would be lame. Besides, as far as I know, TWL never played that much of a role in the early, Gygax-created adventures and first-generation adventure modules, which the show is drawing from, whereas Lolth totally did. Lolth is a vastly superior choice.)
Finally, in classic Hollywood style, Lolth would allow them to cast a beautiful woman as the final villain. Hollywood loves doing that. We won’t go into the psychoanalytic interpretation of this, at this point anyway. Let’s see what they do first….