A voice actor for the upcoming Spider-Man game from Insomniac Games has leaked that Dr. Otto Octavius will be apart of the upcoming title as a villain.
The voice actor named Jai Alex who also voices Rhino in Spider-Man leaked this information in an interview with YouTuber Drift0r. Drift0r was asking Alex about his role in Call of Duty: Black Ops 4 as well as the new Spider-Man, Alex accidentally revealed that "everyone's scaled very differently, Doctor Octopus is really tall, Rhino is big...,"
If Dr. Otto Octavius is the last villain to be showcased this would clear up who is the last member of the Sinister Six, as throughout the comics Octavius was the groups leader at one stage or another. Dr. Otto Octavius could also just be another secondary character as well and we could possibly see more villains revealed moving closer to the release date.