Atlas.

Currently the kingdom is in peace only for thousands of flying monsters to attack thus causing the military to defend.

However Atlas kingdom didn't expect a giant ice worm monster to cause a blizzard thus causing machines to slowly freeze while many soldiers froze to death.

However that ain't all as a monster flying in the air is using some cannon to shoot out many flying ships.

These two are colgera and Wind blight as they are controlled by Ganon who manages to break into the Atlas vault and steal the Staff of creation.

Ganon then walks out of the ruin academy to see that Atlas is retreating which he smirk as he use the staff to recreate the floating kingdom into his fortress.

Ganon: "From now on the Kingdom of Atlas is no more for it now be the Kingdom of Darkness!" He said as he then absorbed the staff into himself thus giving him power of creation.

Union academy.

It wasn't long until reports of Atlas fallen reach Union which shock them as they never imagined that Atlas could fall to the Dark Forces.

But they realized that without both the Underworld and kingdom of Atlas they must house the devils and the military of Atlas yet they know that they can't refuse otherwise they lost the war against the Dark Forces.

Land of Darkness.

Currently the League of Darkness are surprised to learn that both the Underworld and the kingdom of Atlas has fallen to the Dark Forces.

Yet they are planning to force the Dark Forces to kneel before them not realizing that they will lose against the Dark Forces.