Allowing the Spirit Body to receive protection of a dream to slow down the encroachment of danger at night… This is similar to the necessity to sleep when night fell in the ruins of the battlefield of the gods…
Also, the powers in the Forsaken Land of the Gods likely isn't under the Goddess's control. Once one vanishes in the darkness over there, they definitely won't enter the foggy town… Where will it point towards? Or would they stay in the same spot, unable to interact with companions and the real world until they die of starvation or old age… After reading Arrodes's reply, Klein was somewhat enlightened as he roughly grasped the crux of the issue.
