Depends if you're looking for system-specific stats or just for ideas. For M&M3e there's Rogues Gallery and Threat Reports from Green Ronin, but also a load of 3rd party stuff if you're willing to poke around DriveThruRPG. Rogues Renegades and Rivals is a good 3rd party line, as is Algernon Files (sadly abandoned early in M&M3e, the 2e version was more complete)
But pretty much every superhero game has a comparable book (or books) that you could use for inspiration. M&M and S5E are the closest you'll get to d20, though you'll still need to do some not-insignificant conversion work from M&M.