Mark Chance
Boingy! Boingy!
Opps forgot to add that. It superhero with mythical and legendary heroes being reincarnated. It's an "All Myths are True" setting.
In that case, borrow from myths. For example, from Book III of The Iliad: "When the companies were thus arrayed, each under its own captain, the Trojans advanced as a flight of wild fowl or cranes that scream overhead when rain and winter drive them over the flowing waters of Oceanus to bring death and destruction on the Pygmies...."
Yes, that's right: seasonal invasions of screaming flocks of birds that bring death and destruction.