In the world of Thagnarost, on the continent of Flinquet, the Halogen Empire is invading the Relhal Monarchy. Being the only survivors of their destroyed town, Samuel and Michael Cross are rescued by a faction of genetically augmented religious zealots who call themselves, "Uziels." These "Uziels," who name themselves in honor of the angel they worship, train the boys to be the most fierce and deadly combatants among their ranks. Now the end of the war draws close, with both the brothers and their close allies being the enforcers to end the holy war.