Necromancy

Necromancy is one of the five types of magic known to mankind.
Necromancy can't be used to its full extent untill one goes through a transformation. This transformation requires for one to store their soul into a container known as a phylactery. This transformation makes one into a skeletal being capable of doing great feats of necromantic magic called a Lich.
One that became a lich can turn back by taking his soul back from the phylactery. But losing his powers in the process.
The exact way how to become a lich is unknown to most people. And the exact number of active liches is also unknown.
Most liches are in Ruik.