The Opposite
Spazmatism
As an idea for a class based around one of the mobs, how about a cultist who has different buffs depending on the phase of the moon? So, your play style has to change every night. They could start with a Sextant to make things easier, and/or perhaps have a passive that makes them always see the sky as night. For an activated ability (though I'm not sold on the idea of those), they could consume fallen stars while the button is held, releasing to summon a charge-up meteor.
I love this idea. The cultists are badass!