The Eclipse
Natural eclipses are not extraordinarily rare, and in some instances are looked forward to. The moons play a vital role in the land, and can effect the personalities of people. It effects those that are affiliated with magic the most. The moons also represent natural truths concerning the world. So when they are darkened or disturbed, they negatively affect the world below. An example of this would be the moon associated with the Arcane. When it moves further from the world, or is dimmed those who practice the arcane arts find themselves weakened, lethargic, or simply unmotivated until it returns to its glory. Furthermore, the arcane moon is associated with intelligence and financial energy. Those that are in business are warned to be extra cautious. Lastly, that moon has the most dominion over the seas, so sailors are well advised to stay home.
During The Eclipse, the greatest and unnatural, the lands and seas were changed forever. The lens in which people studied the starts, seeking guidance was corrupted, as something out of our own understanding awoke once more. The world was cast into chaos, creatures of the outer darkness took flesh and terrorized lands, beast and man were twisted into abominations. As whatever caused The Eclipse returned to its slumbering state the constellations realigned, and the four moons shone their light once more. As years passed, many forgot the extent of what they had witnessed, and those that remember became figures haunted by a dark truth. It is something that few can speak of.
Manifestation
The four moons, each of which greatly influences an aspect of our lives, were cast out of their natural orbit, though momentarily, as a deafening noise like the grinding of metal filled the night sky. All forms of magic Arcane, Divine, Nature, and strength were weakened, and the powers of mortals stolen from them. The sun was darkened, and the moons cast no reflection.
Localization
It was beholden from across the world, as the moons and stars left their natural state, shaking with dread. Places, such as the Underdark, while they did not see it took the blunt of its woes.
Type
Metaphysical, Supernatural
I really adored how you began your explanation of this destructive event by contextualizing it with the garden variety version. It was a really effective tool for giving an appreciation for the role of the moons in everyday life and how particular catastrophic the eclipse of all four would be. The three questions I was left intrigued by were what the domains of the three other moons are (a little outside this prompt however so fair enough not to include them haha), how long the eclipse lasted for, and how long its been since? Really enjoyed reading!
Thanks for the feedback! The four moons, and the eclipse itself, are definitely a work in progress, so my answer will probably change twice before it's finalized. I'm thinking Nature magic would be associated with wisdom and emotional energy for the second moon, and Divine magic associated with spiritual energy and charisma for the third moon. The last moon I think would 'the magic within', or the magic of non-magical individuals haha. I think the eclipse itself would have happened within two or three hours, though depending on the location it would have appeared near instant, or have seemed to be several hours for the instant effects to clear off, for the most part. I'm planning for there to have been somewhere between 100-300 years having passed since the event. Long enough for people to have rebuilt anyways.
Love the magic within / non-magic manifesting individuals angle for the fourth moon! Really interesting basis, best of luck with the development of it all.