If no deity can achieve omniscience and omnipotence, then no matter how strong the existence, how domineering the race, or how prosperous the civilization, there will come a day that it perishes; it's only a matter of time.
Countless once-powerful races and civilizations have already been submerged in the river of time, perhaps leaving no trace in the real world, washed away to the point of nothingness.
But while material things are easily destroyed, the spirit remains eternal.
The phantoms of those ancient existences still linger in the Spirit World, where this realm preserves all past phantoms completely and permanently.
Therefore, in this world, there are frequently tales of someone sleepwalking, adventuring in the Spirit World, accidentally stumbling upon some ancient ruins, and receiving lost treasures from vanished civilizations, soaring to new heights from there.
In fact, many of the major civilized races today have come to prominence and developed precisely in this way.
