Escape from Kreludor! (irrelevant title)
"Alright, I think that's everybody!" said Kai, grinning as usual. "I think the ship can leave now!"
"No," said Doctor Zhai. "Not yet. Kai, you're going to the safe place with them."
"What? I have to stay and fight!"
"He's right, Doctor," added Hua. "We need him."
Doctor looked at their hopeful, pleading, desperate faces, and said, "Kai no longer has any of his powers."