The sword is Conan's Atlantean Sword from the Arnold movies. "where did it come from", the soviets had earlier thrown a bunch of weapons into the pit for the fighters.
Eddie's death was pretty dumb, but great character and Master of Puppets was awesome.
Wonder why Max's "thoughts" are empty from 11's point of view. 11's abilities also felt a bit wonky, the way she can just hop through people's thoughts was a bit unsatisfying. It didn't really follow the usual rule of "the person whose head you are in is absolute master of this domain" ala Fringe, Inception, etc.
Max getting her bones cracked was FUCKED UP
Interesting post about Vecna from a guy who worked on D&D, Vecna is apparently a lich in a specific campaign which lines up a lot with what we see. Vecna's soul is probably in the clock and he will regenerate like a Lich until its destroyed.
www.reddit.com/r/StrangerThings/comments/vq51ka/im_a_dd_expert_with_some_insight_on_season_4s/
Vecna's whole scene explaining how the Upside Down was at first was pretty awesome, season 5 I'm pretty sure at this point will be the Mind Flayer being freed from Vecna's control and shown as a benevolent being/tool, not an evil Elder God