I think the Vulture would be a good villain if paired up with someone like the Lizard or Electro.
Why didn't I think of that? We could group Vulture and Lizard! That could actually be pretty cool.
Okay, I'm making this up as I go along....
So, Toomes buys Oscorp (I still think that's a great idea), and begins to stabilize it. Plus, maybe Connors works for Oscorp (it was never specified in previous movies what he does when he's not teaching). Still, however, their funds are low after all the hell the company's been through lately, so both Toomes and Connors are struggling through their positions.
In need of a breakthrough, Toomes lends most of Oscorp's money to Connors, who proposes the idea of regenerating lost limbs. However, as Connors continues through his experiments, Toomes believes that his results are insane (I mean, c'mon - lizard DNA to regrow arms?). Meanwhile, Toomes rediscovers the old notes on the glider technology, and, deciding that would be more profitable, lends his money toward that research.
But of course, having become personally invested in his work, Connors proceeds anyway, and, for lack of a test subject, uses himself. When detectives draw the connection between the Lizard and Oscorp, Toomes is driven to the ground but his rivals.
Desperate and infuriated, Toomes dons his wings and seeks out the Lizard. He manages to find the monster, and direct his savage instincts against his competitors, as Oscorp begins to win back profit....
Peter, meanwhile, had been assisting Connors in his experiments before their funding was cut, and became closer to him, so when he hears about his friend's transformation, he seeks to save him. But of course, with the Vulture's interference, Spider-Man finds himself battling more than just a primal monster, and must stop the Vulture as well if he wants to cure his friend.
Yeah if they do a Sinister Six, it needs to be Rhino, Shocker, return of Sandman, Scorpion, Kraven, and Hobgoblin hired by Kingpin.
Another reason I don't want the Sinister Six: in my mind, they're
all common thugs with the exception of maybe one or two.
The first line-up was Ock, Electro, Kraven, Mysterio, Sandman, and Vulture. All ordinary, basically motivated villains with Ock being the one mastermind.
Second line-up: Ock, Electro, Mysterio, Sandman, Vulture, and Hobgoblin IV. Also all basic villains (this was Macendale, not Kingsley) except for Ock (mastermind and traitor) and Sandman (who had gone straight by this point and, if I remember correctly, was threatened - though it may have been an alternate motive....).
Next line-up (I think this is right): Sandman, Electro, Mysterio, Vulture, Kraven II, and Venom. They all had the same motive - revenge on Ock for his betrayal. And then Venom joined and (though I still haven't read part 2, to be honest) just wanted in on the beating-up-Spidey and wound up eating Sandman.
First Insidious Six: Ock, Scorpion, Rhino, Shocker, Mysterio, and Chameleon, taking orders from Kingpin. And absolutely none of them stood out.
Second Insidious Six: Ock, Scorpion, Rhino, Shocker, Vulture, and Chameleon, taking orders from Kingpin. Only special mention here is Chameleon's betrayal.
TSSM First Line-up: Ock, Electro, Vulture, Shocker, Sandman, Rhino. Ock's the mastermind, the rest are goons.
TSSM Second Line-up: Electro, Vulture, Sandman, Rhino, Mysterio, Kraven. None stood out, though they were taking orders from MP.
But in the movies, if villains are brought back from previous movies, more is expected from them than being mere goons. So unless you introduce 4 or 5
new villains, it can't work. Now
that's what I call overboard.