Anathema

The Immaculate Philosophy teaches that Anathema are evil spirits that possess normal mortals and consume their soul, taking the place of the original host.

Historical

The Anathema ruled over Creation with an iron fist in the time before the Shogunate. When the Immaculate Dragons, paragons of the Dragon-Blooded, rose up against their demonic masters, all of humanity was freed. The Immaculate Philosophy teaches that although they were able to cast down the Anathema, the spirits of the Anathema escaped to possess mortals.

Wyld Hunt

The Shogunate, and the current Realm, organised the Wyld Hunt to deal with the Anathema threat. A powerful coalition of Dynastic Terrestrials and Immaculate Monks, they hunt down any sighting of Anathemic Spirits and kill the hosts.

Modern Times

Recently, the frequency of Anathemic possession has increased dramatically - one of the most popular theories on the missing Empress is that she is seeking out a cause for this.
One of the most recent Anathema is the Bull of the North, once an Icewalker barbarian. The Bull of the North has brought House Tepet low after a protracted campaign in the cold of the North.
The most infamous Anathema is known as Ma-Ha-Suchi. While his existence is kept as secret as possible from Creation at large, he is purported to have survived since the overthrow of the Anathema.