According to legend, the Bird of Fire called the Phoenix is the eternal spirit of life, death and rebirth. She oversees the cycle of reincarnation and the rising and falling of civilizations and species. Those who can obtain her blood will be granted eternal life, while to others she can grant infinite wisdom, or eternal suffering.

Throughout history, from the dawn of civilization to the extinction of the human race, those human souls touched by the Phoenix have hunted her over and over in multiple reincarnations, and their actions in one life determine or reflect the sins and sufferings of other lifetimes.