largest moon and only-rising moon in this cosmos, hosting a vast array of lifeforms

A bit bigger than Earth's moon?

Covered in a pale white forest of ginormous trees of incredible shape (boab/ banyan) (fed by a vast underground water network), though from Azafát it looks like it's just pale white and kind of fuzzy. Trees are broken up occasionally by wide mesas and geysers, where the water has burst from underground and shaped the earth around it.

Cold, but largely windless

Mostly in underground networks or spouting from a huge geysers
[Chemical?]

The Threads

The thread-rains on Reigín are most harmful than on other planets due to how raw they are at that stage of shredding. Some are still sharp fragments, and those that have churned into Threads are so potent that it would cause a horrible rash to those unaccustomed.

a vast array of lifeforms, though very few are indigenous to the planet itself. (See 'History')

• The court language of Regín is a creole of Old Vagapariñe, Esolan, and Regini (emphasis on Old Vagapariñe)

Esole: the same as Azafát and The Middle Moon

The Middle Moon (?)

Centuries ago, around the time that Fragmát shattered, the planet had a significant population crisis, and the dwindling population had to resort to pulling beings from Azafát and Esole (the sun) to survive. The government is made up, intentionally, of a mix of native folk and “elected,” the rulership forming a corpus, with each representative aptly given the name of a body part (the ruler is the “Mind Regent,” cosmic ambassadors the “Eye-Knights,” and so on). This was lifted form an obscenely ancient order of knights, whose previous mission has been lost to time. With the population crisis, however, the Reigini scoured through their archives for a solution, and came upon old tales of the Corpus, and with the little information completely remodeled their government from the legends.