Garlemald uses troops of ala mhigo and others as invading troops after 15 years of brainwashing them. That's why they even have mages in their ranks.

They think their cause is just because they got told every single day.

Because wild tribes summoning primals which drain the ether.

Because being free and not under imperial order leads to chaos and anarchy.

As for now, I bet, the story puts of with the dragon eyes thrown into the abyss and east shroud as starting point towards ala mhigo/xelphatol