The Beasts

The Beasts is a lost Faction of feral Destroyer Adepts who now roam the world, lost in their hate and anger after giving in too many times to the beast within. Beasts are terrible Adepts, for they are driven by an ever present sense of anger that drives them onward. What's worse... the bite of a Beast is contagious and those with much anger in their own hearts can easily become infected, in time becoming a feral Beast themselves! 
Luckily, Beasts are anti-social monsters of rage who dwell in the removed and rarely visited places of the world. Each Beast suffers from a form of retrograde evolution (each is a Troglodyte), with most of them growing thick fur (which is almost always jet black), claws and fangs, glowing red eyes and occasionally other animalistic accouterments (horns, tails, hoofs, etc.). 
== Beast of Rage: ==
No one knows the name of the first Beast, they have been around for thousands of years. When a Destroyer is bitten by a fellow Destroyer who is infected, a supernatural curse is passed on to the target victim. If the Destroyer in question can't handle the explosion of hate and anger within him, he'll become infected and quickly transform into a Beast himself within the next 24 hours.
Non-Destroyers can be infected as well, but they are unable to pass on the curse through a bite.
Removing the curse is difficult to say the least. Exorcism is said to work but it's a grueling and difficult process. Another method is to kill the initial Beast who infected them, although this has been met with mixed results and acceptance. 
== Dark Secret of The Destroyer Order: ==
The Order of Destroyers is loath to speak of the Beasts to outsiders, even to other Adepts. Some Adepts aren't even aware they exist in the world! The Destroyers represent the destructive side of God, and by extension the destructive side of religion. The mystics among the Order believe the Beasts are a sanction by God Himself to keep the Destroyers on the straight and narrow, forcing them to confront their own bias and prejudices (and fears) and keep them from acting out on others.
Considering the Destroyers are often embroiled in political struggles and culture wars, the idea that the Beasts are a sort of stop gap from God doesn't sound quite so implausible. At least not to those in the know, which is surprisingly few.