In my alternative universe, Cadence is the Tree of Harmony itself, taking on a pony form to maintain harmony, at least in a small part of Equestria.
Her kingdom is designed to help “normal” ponies. It is meant to be a peaceful place where any pony race can come and trade. (As long as they behave)
The habitat is livable for both night and day creatures. In my AU, the pony races are divided.
Some stayed with Nightmare Moon and became the bat ponies we love so much. Most of the pegasi remained in the dark.
Most unicorns followed Daybreaker and adapted to the harsh, desert-like environment. Their magic became more harmful for survival, though some still strive to learn as much as they can about magic.
In Cadence’s kingdom, the crystal and earth ponies find peace, trying to live peacefully while the ongoing war remains outside the crystal walls.