When it comes to the mastermind villains, the only few that are supers are Octavius and Osborn. However, Spidey has a lot of mobster villians as well who could fit the mastermind (main villain) role whereas a small time supervillain could be around as well. I found the idea in Spectacular that the supervillains like Sandman, Rhino, and Shocker were paid for by a mob boss to be created simply to distract Spidey while normal crooks do small time crimes elsewhere genius.
Since Kingpin is locked up with Fox. I could see Tombstone being a crime boss now thanks to Spectacular making him the Big Man. He also seems to be an interesting mix between normal criminal and supervillain, a "freak" crime boss if you will. Heck I have to say Spectacular did an amazing job with Tombstone, since he was always was just a lackey in the comics and was more of Robbie Robertson's villain. It worked surprisingly well and he just works as a crime boss.