There are three possible ways a sentient being can become an abomination. The being can be possessed by a ghost, spirit or another other worldly being. This possession can only be held for a short time compared to the other two. The second form is via ritualistic entrapment. Through powerful rituals and spells an entity can be sealed within another. This possession is permanent and lasts until one of the two forces succumbs to the other. The third, final and most common form of an abomination is the host being born with the entity already sealed inside. This form almost always can be identified with signature birthmarks representing whatever entity is sealed with in. Abominations are feared for their power and hated for their evil.
The first abominations were created by the Dark One while he was trapped in his eternal prison. Designed to be super soldier capable of unimaginable power the Dark One created them with all his power and unleashed them into the world, 79 in total. These entities proved too powerful for the now weaked Dark One to control and they rebelled, content to act upon their own desires. These first abominations became known as the "Septuaginatnovem Larvae." Which is ancient tongue for "The 79 evil spirits."
After the Dark One's first failure with creating servants in the world he opted for less powerful but more obiedent minions. Thus he created the second wave of abominations. These new evils were far more numeous but not as powerful or self serving. Instead these monstrasities are perfectly fine with causing as much pain, death and suffering as possible right until they are killed.
Abominations, both normal and larva share some common properties. The first similarity is that no abomination is alike. Each is entirely unique in appearance, desires and rational. They do, however, share a natural desposition to killing and destruction. Both also cannot be killed by conventional means. Simply killing an abomination as it normally is only achieves in sending the evil back into the void to be born inside yet another victim. Abominations must be ritually scarficed in special temples to purge them of the evil and destroy it entirely. This method, however, is only successful at killing normal and untransformed abominations. Unfortunately if the host is unlucky enough to be possessed by a larva then the sacrifice simply sends the entity to be reborn a 100 years later. (And normal killing of the host causes it to be reborn to the next child who is born.) Most chose to sacrifice themselves and destroy the monster that the Dark One had planted in them. Others chose to find a way to overcome the beast within them, only to later be eaten alive by it, and still others chose to accept their fates at destroyers. If they so chose to become the evil within, becoming a transformed abomination, then defeating the transformed abomination would also effectively kill the evil permently, but that was often a task easier said then done. (Thus the popularity of the ritual sacrifice) A fully transformed abomination often looks little like a human and more like the unholy horror that most people assume. The transformed abomination boast more power, although a very evil one, than an untransformed one could ever achieve. Once an abomination has fully transformed there is nothing left of the host's mind or spirit, only the entity originally sealed remains.
Recently The Four sent spirits to reside in special temples that were capable of purging the evil from the abomination without killingthe host. This process is long, dangerous and horribly ineffective against the Larvae. To date there have been only seven legitamate documented reports of actual Larvae as being the source of abominations. Five were successfully purged and sent away only to return years later. Two, however, resulted in the releasing of untold horrors upon the world. Only one of which was killed which implies that another may still lurk the world.
Larvae (Lar-why) have shown far more dangerous and rarer qualities through the few encounters with them. For starters Larvae are not only sentient but usually extremely intelligent. Each Larvae has its own distinctive personality, appearance, powers, and agenda. A Larva's power far exceeds any normal abominations potential power and Larva are capable of feats of terrifying magnitude. Although they usually appear to speak in an unknown demonic tongue, when communicating with mortals the ancient tongue was used. The Larva, Rikulifal (Re-cool-lee-foul), was shown to enjoy taunting its opponents.