In the Movie universe, after making that deal with Sentinel, Megatron was planning to meet him in Earth. But, at the same time, he was working for The Fallen. What if the plans he had with each of them had been successful? At some moment he would have both Sentinel and the Fallen together. Maybe he was planning to have them both destroying each other? Or maybe Sentinel, trying to save his race whatever the cost, had allied with The Fallen (with The Fallen, being the older and more powerlful, having two "apprentices")? What scenarios can you think about in this case?