Cold is the only temperature the island nation of Frostica gets. Just varying temperatures that are cold. And what would you expect from a nation called Frostica?
However, some rather though humans actually lived there, in an area known as Lower Frostica, which was the least coldest area in on the island. There were, of course, attempts to colonize Upper Frostica, but the temperature usually kills everything. Expect one kind of living thing, the Frostites.
The Frostites were made by a long deceased Wizard who is also believed to be responsible for creating Frostica itself. Due to this assumption, the Frostites worship the wizard like a god.
The Frostites wanted the humans off their island. They belived since they were created by the wizard, they were his children, and now they inherited his kingdom, which was, a surprisingly legal reason. He humans thought they since the wizard probably died hundreds of years ago, they couldn’t claim the island. They also said the wizard never named a heir, which was also a fair point. And so a war just had to start.
The Frosticans did, ally, Magmosa, the polar opposite in temperature. But, they were allies motherless, so they decided to help their cold ally, and enforce their claim.