Horcrux

The precise origins of the magic behind horcruxes are lost to time. The only documentation of their existence is in ancient grimoires in the hands of Gatian magical scholars, such as ZAPS or Medinan Shadow Barons.

In essence, a horcrux is an artifact in which one can store a piece of a soul. The practical upshot of this means that even if the body dies, the being survives, albeit in a noncorporeal state. If one has the means arranged, the disembodied soul can then inhabit a prepared body. If one is not careful, said soul may be trapped in the spiritual realm, unable to return to the mortal coil in any physical state.

A horcrux can be any sort of item, traditionally non-organic in nature. Given that one must literally fracture one's soul into pieces in order to make use of one means it is a fundamentally corruptive magic. Fracturing a soul generally requires committing an evil act, such as coldblooded murder, in order to weaken the soul's cohesiveness. Although there is no concrete proof a horcrux was ever employed by any member of the Defilers, it therefore falls under the blanket heading of Defiling Magic.