You come seeking to know about magic. I can draw back the veil of secrecy. I am the one who understands. Magic starts with the secrets of the soul.
Life is made up of two parts, the Corpus and the Soul. The corpus is what is left behind after the soul has left it. The corpus is not the soul, but during life contains it.
The soul is made up of three parts, the Sanguis, the Iustum, and the Umbra. The sanguis is not the blood of the corpus, but it is related to the blood. The sanguis is the vanetil portion of the soul, a major portion of the magic of the world. While the sanguis is not the blood, as the blood leaves the body so does the sanguis separate from the corpus and thus death creeps in. Of course death can arrive in numerous ways, but in violent deaths, loss of the sanguis is the most common. As life leaves the body, the vanetil sanguis returns to rejoin the magic of the world.
The iustum is that portion of the soul that you mundanes think of when you think of the soul. The iustum moves on to that “just reward” you hear so much about. The iustum is the largest “piece” of the soul if such things can be measured. In fact, the soul is infinite when measured as a thing of power.
The umbra is then the last portion of the soul, the smallest portion and the piece that remains with the corpus after death has taken its toll. The umbra is a shadow that surrounds the body. This is the magic that necromancers tap into in order to work their magic. When these death mages speak with the “soul” it is the umbra that they tap into, for it is the only piece left. While nowhere near as powerful as the iustum, the umbra is still a major source of power.