Okay, so Rung wasn't changing his mind and backing out of this. He was just asking, perhaps for the sake of asking. And that look on the Autobot's face was far too trusting. He was actually ready to go through with this, with letting Dead End eat him. Something the Decepticon is still having trouble understanding.

"No, nothing else."

Rung does look delicious...

"You're sure about this?" he asks once more. Just. Be sure before he actually starts draining some energy from the guy.