During the days of the Fourth Age, the Wan Xian began to fall from grace and began to consume the Chi they were administered to police for themselves and began to set the Xiong Ren against each other with lies, treachery and powers gained from the darkness of Yomi Wan. The Shifters, allied with the Wan Xian since their creation, believed them and began a massacre amongst each other, similar to the War of Rage that decimated the Fera in the West.
As brethren fought brethren, the treacherous Wan Xian glutted themselves on the dragon nests that the werecreatures had originally protected. When the Wan Xian were finally transformed into the dark creatures known as Kuei-jin, the Xiong Ren realized the betrayal and lashed out in savage fury against the civilization of mortals that worshipped their fallen protectors. Afterwards, the Hengeyokai, or Beast Courts, were founded in order to prevent another war amongst those Fera loyal to Gaia.
Many Fera were exterminated during these days, among them the Okuma, the eastern branch of the Gurahl.