The wise sage Ghido speaks of an ancient tree in the Great Forest of Moore where evil spirits were sealed. Over the centuries, the concentration of their malice formed a unified evil being: Exdeath, who wishes to return the world to void. The Warriors of Light must fight him on behalf of the crystals, which created the world within the void.

The crystal amplification devices invented by Cid Previa have brought prosperity to crystal-bearing nations such as Karnak, but has also weakened the crystals. The Light Warriors attempt to save the last crystal, while also learning more about their predecessors: the Dawn Warriors.