Mordrem are aboard the ships.
He should have expected this, of course Mordremoth would send his minions and attack - but Zhaitan couldn't do this, they couldn't have expected Mordremoth to have such complete control over the jungle. Now dozens of thick, thorny vines are shooting out from the jungle at the airships, strong enough to pierce right through, and aboard them are the dragon's minions. Plant humanoids, like himself, but clearly corrupted, twisted into horrible abominations, a mockery of his species. And he fights them, because how could he not? Even though they might all die as the ships come crashing down despite their best efforts.
He casts a Reaper's Mark on the floor, directly in front of an approaching Mordrem; the circular symbol should trigger a fear effect on it once it crosses the mark, if the creature is even capable of feeling fear.