The death and defeat of the God of Light was a giant setback for the Human God System, who had previously been arrogant and mighty.
Although they still had three Divine Powers in their system and were still one of the strongest out of all the races, with the loss of their main leader, the great Divine Power God of Light, they lost the ability to be dictators looming over the other races who were weaker and unable to defend themselves. They also had to concentrate on gathering their powers as a defense to prevent themselves from being attacked and hunted by the surrounding races who wanted them dead.