This is how The Final Battle with the Fallen goes in
[Twilight walks over to the defeated Megatron, who is held at the mercy of Twilight and crawls away. Twilight prepares a ball of magic as the Fallen looks on impress at Twilight for her efforts. Twilight approaches Megatron as the Fallen gets up from his throne and goes over to join her]
The Fallen: Yes. Kill him. He is weak, broken. Kill him and you can take your rightful place at my side.
Sunset Shimmer: No!
[Sunset takes out the two guards and runs to the Fallen, who blasts her with lightning. Optimus looks at Twilight]
Optimus Prime: Help her!
[Twilight looks at Megatron, who's getting back up, and at the Fallen, who's still blasting Sunset]
The Fallen: You had such promise, Twilight. You could've been my successor, my equal.
Twilight Sparkle: I would never.
The Fallen: But now...I would've still had small use for you. I still had enemies to find and destroy. You would've done my bidding until I found a new apprentice. And then, like Megatron, you would've been cast aside.
Twilight Sparkle: The Princess of Friendship doesn't give in to her anger.