Necromancy

Our Lady is patient Rosemary. Were it not for necromancy we likely wouldn't be needed. But there is a need and it is wretched indeed.

Necromancy is not what the fantasies might tell you. There is no broody and misunderstood practitioner. There is no argument to make to bring them back into the light. You are better to try to convince plain serial killer then a necromancer for those may simply perform those atrocities for their own mortal delights. Necromancers do that and take it beyond. The necromancers that begin insane do not last long. The powers any necromancer must court consumes them quickly. It is those that go in with every understanding of why they should not that are the most dangerous.
Necromancers can be desperate for many reasons perhaps they did loose a loved one tragically or perhaps they didn't. Regardless any sane even remotely benevolent being should see the atrocity that necromancy commits against a soul and inhale acid before involving themselves with it.

Definition

Necromancy is specifically defined as:

The artificial binding of a soul to the mortal realm through the grafting, twisting, or otherwise warping manipulation of their or another's thread of life.

This notably defines very few supposedly undead creatures as a product of necromancy. Under this definition as defined and accepted by the Greater Aspects of Death, who are the leading experts on being dead, dictates that undeath is defined via process of the spirits presence in the mortal realm. Not the spirit's presence in the mortal realm in of itself. The strain necromancy puts on a spirit is innately harmful and can cause long lasting damage to a form that is not meant to take any.

Practitioners

Necromancers include solely those that have actively participated in necromancy. This can make necromantic cults difficult to track as there are ways to prevent magical traces from adjacent acolytes as they are called. Groups of necromancers are called a cult due to both the recruitment methods and the methods of internal organization. It has been noted that those integrated into a necromantic cult were either in a position of power with a craving for more or in a position of desperation or despair where necromancy was made out to be a misunderstood salvation. Those in the latter group do not often discover the truth of the group they joined until it is too late. Those that have the will to break away from the cults teachings are killed quickly and violently bound so as not to have any chance of revealing the cults hideouts.