Mysterio could be a really interesting character. He's been utilized in so many different way about like the Joker and Riddler it's hard to get a good perspective because you don't know if you're going to get a more cheesey, slapstick version or dark and menacing version. I have faith in the MCU to keep this in check. I don't think we will get a bunch of cheap party-tricks and someone that's under-powered. I get with the comics you have to watch how much spotlight you give which villain as you have to keep a heirarchy in place. You don't want to create a "super villian" and stifle the build up if you're leading up to a green gob, hob gob, venom, carnage, etc. they're going to have to make Mysterio interesting, start up a sinister six arch, and leave a little room for whoever the ultimate baddy is going to be.