Cloud of Darkness is the final boss of Final Fantasy III. She manipulates the villain Xande into destroying the crystals so that he would unwittingly summon her forth. Cloud of Darkness's aim is to reduce the World of Light into a void of nothingness. Though she manages to defeat the Warriors of Light, the strength of the warriors' allies allows them to awaken in the World of Darkness, where they receive the aid of their counterparts of this world, the Warriors of the Dark.
After the Warriors of the Dark sacrifice themselves to give the Warriors of Light a fighting chance, Cloud of Darkness is confronted for a second time, and is defeated.