Year 561 of the Solar Calendar.
According to historical records, that year, red rain fell from the sky and monsters arose from the earth. Natural disasters struck one after another, and internal strife was rife. The Beastman Empire's invasion and the threat of dragons left humanity beset on all sides and pushed to the brink of extinction.
To survive, humans and spirit beasts, the two weakest races, formed a pact. Later generations called that day the Day of Revival: the beginning of humanity's renewed hope, and the beginning of its counterattack.
They were known as Spirit Envoys.
