God's Creation

•The universe and the earth were created by the "nameless God". •God sets the rules: the civilization of each era will reach its peak, then be destroyed, and then usher in a new era. •Civilization in each era will not disappear completely, but will affect the next era in the form of afterimages, ruins, myths, genetic memories, etc. •The protagonist is a being who can travel through the "long river of eras" (maybe a spokesperson for God, a rebel, or a mortal who awakens unexpectedly).