Afterwards, Thor and Hercules go back to Earth and they get a quick fight against Destroyer before we get some very cool Galactus stuff. And frankly, we’re due for a really good Thor comic at this point.
Firelord is a herald of Galactus. He’s come to Earth to recruit Thor to help Galactus fight Ego the Living Planet. And check out Galactus’ boss ride…
Ego has gone crazy and he’s blowing shit up-and Galactus is displeased because planets are his food source. Ego is wasting food, basically.
Over the course of the tale, the heroes go to Ego, fight personifications of Ego on his surface, and then send him on his way, vanquished.
At the end of the story, Firelord wants to quit his job as herald (Galactus can’t seem to keep good help!), so Thor and Hercules give him the Destroyer robot, which they defeated at the beginning of the story, and Galactus gives it the power cosmic.
Thus, Destroyer is now the Herald of Galactus.