Artistic License – Physics: When Megatron rams Starscream in the air, both of them just stand in place for a second. The collision should have knocked one or both of them hundreds of meters away. Of course, this could've just been for stylistic purposes.
At Least I Admit It: Megatron, as prideful as he is, is willing to admit that he’s made some mistakes, and he very much intends to rectify his greatest one yet.
Big "NO!": Starscream, as Megatron drags him away for the punishment he's intending to deliver.
Big "WHAT?!": Raf when told that Megatron is possessing Bumblebee.
Converse with the Unconscious: Raf tells Bumblebee a story while playing a racing game while the latter is powered down. Ratchet brings up that Bumblebee can't hear him in this state.
Ironic Echo: Megatron taunts a groveling Starscream with the latter's words from only moments before.
Starscream: The Autobots...Optimus...right there...waiting for you!
Megatron: My 'greatest mistake'? I've made a few. But there is one I do not intend to make again!
Jerk with a Heart of Gold: Ratchet is initially uninterested in Raf talking about feeling ignored by his rather large family, but he's touched when told Bumblebee always listens.
Karma Houdini: Megatron faces no comeuppance for what he does in this episode.
Fowler: Prime, you spot any Decepticons wearing hula skirts lately?
Mind-Control Eyes: When Bumblebee's eyes shrink, it's a sign of Megatron taking control.
Mass "Oh, Crap!": Everyone is shocked to see Megatron back in action, especially Starscream, who no doubt sprung an oil leak upon seeing him alive and about to dish out punishment.
My God, What Have I Done?: Ratchet over missing the warning signs of what was happening to Bumblebee.
Motive Rant: Starscream is doing this when talking to Megatron's body about the comatose state and how he will prove once and for all who the true leader is. Knock Out interrupts just as Starscream describes the details of his plan.
Starscream: Lord Megatron? You are...you're healed! Praise the AllSpark! It is a miracle!
Megatron: Oh, it will be a miracle all right, Starscream...if you survive what I have planned for you!
The Only One Allowed to Defeat You: Megatron stops Starscream from killing Optimus because of this. Also, he was planning to punish Starscream for his failed attempt on his life.
Megatron quickly gets moving trying to return to his own body, as he's certain Optimus will soon notice Bumblebee's increasingly odd behavior and put the pieces together.
The Autobots have to stop Starscream's plan before the glacier melts and causes coastal cities to be flooded.
Megatron's frustrated response to Raf being on the Nemesis and getting through to Bumblebee.
Also, Starscream's reaction to Megatron's return to functionality.
Villainous Rescue: Megatron stops Starscream just before he can finish off Optimus. Half because that honor is his alone, and half because he intends to punish Starscream.
Would Hurt a Child: Megatron knocks Raf across the room for interfering.
Wrong Assumption: Ratchet initially thinks the cortical psychic patch affected Bumblebee in a way that's causing him to act like a Decepticon. It takes going over all the details for him to realize it's much worse than that.
