Ultimate Spider-Man: Fallout of Sinister Six Arc
In the current arc for Ultimate Spider-Man, we see that Peter & Harry have been captured by Kraven and now will be forced to either kill Kraven or successfully be hunted. I think this creates an interesting situation because clearly Harry is more willing to use lethal force than Peter. Peter, however, is resistant to use lethal force and true to his 616 self, prefers a more diplomatic approach when possible. I think this will create a rift between Peter and Harry as the repercussions of Peter not taking his opportunities when presented to kill a member of the Sinister Six will result in a pivotal moment...the death of Gwen Stacy.
While I think it's likely that Harry will leave the Kraven situation stricken with feelings of powerlessness when he's not wearing the Goblin armor, something that can be addressed with a Goblin serum, I think he will still be willing to trust Peter and be his friend. However, we do know they have or will have faced the following gauntlet of Sinister Six members:
- Black Cat
- Kraven the Hunter
- Mysterio
- Mole Man
- Mister Negative
- Kingpin
Personally, I think Harry and Peter will physically defeat Kraven but not kill him. Kraven will face his fate due to the threats naturally existing in Mole Man's subterranean kingdom which Kraven will respect as an honorable fate due to him being "hunted" by the dinosaur/animal/monster or something along those lines. However, based on covers, Mysterio is likely the next member to take on an active role in trying to kill Harry and Peter. To make matters more complicated, the Sinister Six members clearly know their identities and family members. This all feels like details to set up the possibility that the Sinister Six makes a move upon one of their families which Harry making the most sense.
The reason why Harry and Gwen make the most sense as the Sinister Six target is because they are the more dangerous threat overall. Peter has actual superhuman abilities but he has a moral code against killing and MJ is a Marketing/PR executive which can only do so much damage. On the other hand, Harry and Gwen are risks due to Harry's willingness to use lethal force and Oscorp resources. I wouldn't be surprised if Kingpin, as leader of the Sinister Six, has a petty grudge against Gwen for funding The Paper which exposed his criminal activities to the public. Based on future advertisements for Ultimate Spider-Man, it seems likely that the Sinister Six arc concludes by issue #20. The reason I say this is because issue #24 or #25 will be around the time where The Maker can once again leave The City. It would make sense for the Sinister Six arc to wrap up and then a mini-arc to happen between issue #20-24/25.
My best guess is that the Sinister Six will be trimmed down to three surviving members by the end of the arc -- Mister Negative, Mole Man, and Kingpin. I think Mole Man checks out of the conflict in favor of prioritizing time in his subterranean home because he seems the least interested in getting involved compared to the other members. Mister Negative will be defeated and Kingpin will be the last member of the Sinister Six standing. Kingpin will be able to identify that Harry is more vulnerable than Peter thus go after ways to break his spirit - resulting in the orchestration of Gwen Stacy's death.
The death of Gwen will be the breaking point for Harry who will blame Peter and his inability to eliminate the clear threat of the Sinister Six which allowed them to learn their identities and Kingpin to orchestrate Gwen's death. Harry will attempt to personally go after the Kingpin without any restraint which likely results in a lot of collateral damage and Peter being forced to stop Harry which firmly places them at odds against each other. I think Harry will depart the series for an undisclosed period of time after this and later return in a future arc with the Goblin serum and attempt to enact revenge on Peter.
If this plays out like this I could see Uncle Ben dying from Harry's actions, maybe he's trying to investigate what is going on and dies in a similar manner to Captain Stacy from Earth-616. This could serve as a seed of division between Peter and his son Richard, who is currently the most likely host for Venom depending on how AI Peter also handles the death of Uncle Ben.