On a continent overrun by Chaos-born monsters, the lords who are supposed to fight it back instead war among themselves over the holy Crests that grant power. Siluca Meletes, a gifted young mage disgusted by the lords' greed, allies with Theo Cornaro, a knight who earns a Crest by killing a monster himself rather than inheriting one. This manga follows their attempt to unite the continent's warring factions under a rule that actually holds back the Chaos.