11 Potential Villains For MCU's Sinister Six

Yes, Mysterio died (or "died") at the end of Far From Home, and yes, he's the master of illusions, so that all could've been an elaborate ruse. While many are (reasonably) of the opinion that Quentin Beck is well and truly dead, Marvel could feasibly come up with a way to work around his apparent onscreen death if they wanted to bring him back.

He was also a member of the original Sinister Six, so for that reason, he gets a few brownie points as a potential choice.

He posed a threat to Spider-Man in a way that Vulture didn't: Mysterio's manipulations were so powerful, so convincing, and so emotionally and psychologically caustic that Peter - to paraphrase Bucky Barnes - couldn't trust his own mind. While the other villains Spidey has faced have been physical powerhouses that may (in the case of Vulture) or may not (in the case of Shocker) have had some tie to his personal life, none of them have worked their tendrils into Peter's psyche and made him doubt himself the way Mysterio did.

The only reason he's so low on this list is because he REALLY seems to be dead. If he were clearly alive, he'd be much higher.