Fan theory. Spoilers because there’s no way I’m not right.

I think vecnas going to get a redemption arc.

When >!max showed he was scared of the cave, I think that was hinting about whatever gave him his powers, and it’s probably the same thing that gave will his powers, dust from the mind flayer!<

I think >!Henry creel was an innocent kid, and he’s been trapped in a psychological battle with the mindflayer since the point where he got possessed.!<

I think he’s gonna try to >!use time travel to go back before he had any childhood contact with the upside down, and prevent that from happening which will in turn prevent the entire series from happening.!<

In other words vecna >!is kind of a good guy at heart, trying to fight for control over his mind and his life, in resistance to the mindflayer. He’s bringing kids to the upside down, including will, to power them up and get them enough collective power to fight back against the hive mind and against the upside down itself !<

At the end of the show, the main crew >! Will team up or unwittingly help vecna go through a worm hole to change the past. Then everything will go back to “normal.” No upside down. No eleven. No Hawkins lab. Main kids will be having a safe and innocent d n d campaign where they have a strange sense of dejavu or a one of them suggests major plot points from the show as a possible compaign. Maybe one of the other kids poohpoohs the idea and says it’s too far fetched. Then Mike or will shrug and say, “well stranger things have happened”. !<

Then they look knowingly at the camera, roll end credits.

Then >!an after credits scene shows Brenner trying to create psychic soldiers and some bald kid getting contact with the upside down or a demogorgon!<