A thousand years after a cataclysm split the veil between realms, the world rebuilt itself into four powers: the Light Kingdom, the Black Kingdom, the Silver Kingdom, and the mysterious Vegetal Kingdom. When two unexpected warriors, Kai and Elen, rise from the fragile Light Kingdom and overcome champions from across the others, they ignite suspicion from angels and demons alike. As hidden truths unfold, their powers evolve, and the balance of all four kingdoms—and the fate of heaven and the abyss—rests in their hands.