Finally Megatron and the Insecticons get together with Unicron who fucks up the chemistry lab in the first set. This utterly unexpected turn of events yields the new Galvatron and Sweeps who kill Starscream. The new Galvatron is infinitely more powerful than the old Megatron. For those who are familiar with the movie it's important to note that only with the help of the Junkions can the Autobots bring justice.
I'd written a ton more about the philosophical implications of all this. We need to consider whether the Autobots are subjects of determinism. They might be. They might not be. What about the Decepticons? Do the ordinary rules of metaphysics apply? We assume so. But if they do, why are the Decepticons so difficult to stop?
Probably no one knows.
We are able to see from the image that even some of the Autobots probably have Decepticon transformations (for instance Devastator). Also, the Dinobots represent the Autobots in the siege on Autobot city. Presumably this hybridization is represented well in battles leading up to the second Unicron introduction.