There's still at least one emergency response squad nearby.
"I am needed elsewhere," rumbles Gorthoklek. He addresses the emergency response squad in Infernal. "You. Obey Sevar." A claw indicates the Chelish person in question.
Gorthoklek then launches himself into the air, beating his vast black wings in a way that is blatantly insufficient to actually support his weight in any way whatsoever to the eyes of anyone who has even heard of aeroynamics. When he has risen above the Forbiddance, he teleports out.