If Kraven were still available (and he may eventually be) I would honestly have used a pretty good chunk of the full Kraven family - Sergei as the Big Bad looking for one last great hunt and being a terrifyingly superior foe, Ana as a sympathetic and pitiable but villainous peer for Peter and his friends (imagine her tracking Peter’s civilian guise and stumbling across MJ when Peter goes to see her for some measure of solace), and Chamelon as the insidious, lurking threat. The way to integrate them into Peter’s civilian life story is, again, Ana stalking him and brining his friends (last and current) under potential fire and making Peter feel even more pressure to drop most of his civilian life (which he actually needs to stay mentally healthy.)
Scorpion is a great muscle villain, and one that might be elevated by Michael Mando’s pure intensity and skill, though he feels to me like he would benefit greatly from having some boss above him. Honestly, I would love it if he was, say, a prisoner volunteer for a Spider-Slayer program funded by Fisk and Jameson, who gets an updated and upgraded enhancement after a decent chunk of the film is the earlier Spider-Slayers giving Smythe data, with Scorpion of course being a physically superior but uncontrollable psycho. Part of the comedy here would be Peter having to deliver photos to Jameson knowing the money from the publicity plugs in to the Spider-Slayer program.
Hobgoblin would be a good foil villain if they made him embrace Jason Macendale’s moral cowardice and irresponsibility, and had him “grow” in the film using the same duplicity, ambition, and cunning that the Animated Series version of the character had - conniving to get upgrades from potential employers or patrons to go from simple thug to a major, possibly recurring villain who repeatedly jumps up and down on Peter’s trauma butting because his main transportation and weapon platform is copied from some left-over data Norman left behind. I also think he could potentially have a parallel to Peter’s last involvement with Magic: one way for him to potentially get power would be to make a deal with Mephisto and use some of the Demogoblin stuff for his power. Give him a sword and a mercenary personality, and I think he can be an “heir” to Green Goblin without being a cheap knockoff.
