Radiant Sky

The Radiant Sky is an arcane dome that covers most of the Eimaui Archipelago, save for the northern-most islands (which are usually uninhabited). It has a slight orange tint and ancient runes float around it. The arcane energy contained within emits heat to make the archipelago inhabitatble, especially during the winter, when temperatures would be too low.

Nature and history

It's not quite known when and how the Radiant Sky came to be. Some theories claim that it's an artificial structure, probably created by the early archmages, before the Veil even existed, when magic was much more powerful. Meanwhile, others claim that it's a natural occurrence and that the floating runes are just man-made improvements on an otherwise natural phenomenon.
Regardless of that, the School of Eimai, with the help of the Veil, takes care of maintenance. Every winter the Radiant Sky is thoroughly inspected and if any weakspots are detected, they are reinforced with magic. The Veil's official position is that if the Radiant Sky ever were to fail, they would be able to create a replacement. However, most people doubt that humans could ever create something like this again.

Strategic importance

With a handful of exceptions, Eimai's infrastructure is not prepared to withstand the low temperatures that would occur if the the Radiant Sky was destroyed. As a consequence, it's one of the most important parts of Eimai's defence strategy and historically one of the first things to be attacked when going to war. Additionally, the Radiant Sky is a fully arcane phenomenon (i.e. it has no material components), which means that the only way to destroy it is using magic. This is the reason the School of Eimai tries to keep positive relationships with all other Schools even during way.