Darkness Rising Part 4 is the fourth episode in the mini-series and the fourth episode of Transformers Prime: Friendship is Magic.
Bulkhead, Applejack, Arcee, Rainbow Dash, Bumblebee, Rarity, Smokescreen, and Pinkie Pie sneak on to the Decepticon warship, the Nemesis, to rescue Princss Celestia, while Optimus Prime, Twilight, Fluttershy, and Ratchet fight off Megatron and a horde of Dark Energon zombies.
As Megatron's army of Dark Energon-powered Terrorcons march, Optimus Prime, Twilight, Fluttershy and Ratchet are horrified at the desecration. The Dark Energon flowing through Megatron gives him control over this new army, and he directs them to destroy the two Autobots and their pony allies. When the Terrorcons keep getting up as fast as Optimus and Twilight can blast them down, Ratchet and Fluttershy discover that dismemberment is a more effective way of dealing with them.
Raid on the Nemesis
At the Decepticon ship, Bulkhead rescues Rainbow Dash and Rarity, who are under fire from the Decepticon sentries.