The faction in charge of the Aregis Alliance.
Aregrionno has been a republic for many centuries but with the apparent reinstatement of an emperor in Val Aregis, the (now) Royal Army has started a war to reinstate a monarchy.
The flag represents the blood-red colors of the Aregis Alliance, ruling over all under the (blue) sky.
A soldier of the Royal Army of Aregis in full battle gear. Note the spear, gladius, and large shield.