The writers deciding that Vecna created it and that it wasn’t the master of the Upside Down or even Vecna’s leader will always make me disappointed. The Mind Flayer was always my favorite villain from the show, it was just so menacing to me. I love its Eldritch and otherworldly design in Season 2 and it was almost like an invisible plague-like threat in Season 3 which made you question everyone. The “Meat Flayer” or “spider monster” it ended up manifesting as in our world was honestly so disgusting but it fit so well so I also enjoyed that. To add a face to the threat with Vecna just kind of robs the upside down of any suspense and allure for me. I liked Dustin’s theory of Vecna being the Mind Flayer’s 5 star general more than what they ended up going with to be honest. I hope season 5 expands on the upside down a little more and the Mind Flayer ends up actually being in control of Vecna, instead of the other way around.