Re: Confused about Megatron's plan
Actually, the third film retcons the first two because Megatron's plan doesn't jive with his plan was in the first two films.
In the first film, Sam and the Autobots assume that Megatron wants the Cube to transform human technology and take over the planet. That's their assumption.
Revenge of the Fallen technically retcons that but it makes it fit by saying that Megatron was one of the many Seekers sent to look for the Cube for the Fallen so that the Fallen could find the location of the Matrix of Leadership in order to reactivate the Sun Harvester to harvest our Sun's energy and help rebuild Cybertron.
While having Megatron be someone's ***** in this series was a bad move from the get go, the second film can jive with the first film, easily.
But this third film completely throws all that **** out by openly saying that before Megatron left Cybertron, he made a deal with Sentinel Prime to harness a technology that only Sentinel could use that would bring Cyberton into Earth's orbit, harness the planet's resources and then enslave humanity to rebuild Cyberton for the Decepitcons.
DOES. NOT. JIVE. WITH. THE. FIRST. TWO. FILMS. AT. ALL.