This is how Starscream goes rogue goes in Partners.
[At Autobot Outpost Omega One]
[Starscream breaks the cuffs holding his wings]
Starscream: (voice) I have been a fool. Made mistakes. Monumental ones. But I have gained a clear understanding of my place in the universe. Of who I am. Starscream. Aligned with no side, servant to no one, master of Nightmare Moon, Tirek, the Dazzlings, Tempest Shadow, Queen Chrysalis, and King Sombra.
[Starscream transforms to jet mode and flies off as the episode ends]