Magic involving death was a form of dark side magic utilized by the Hakotei Presagers.
To glimpse visions of what was to come, the Presagers employed living sacrifices, particularly their recent blood. The Presagers required a dark side Force nexus, like those present on Hakotei or Asusto, to wield their magic. Furthermore, they held the conviction that a "conduit" would eventually appear, enabling them to foresee all conceivable futures through their magic. The Presagers thought that a young Dooku, who arrived on Asusto alongside Jedi Master Lene Kostana and her Padawan Sifo-Dyas, was this conduit. The ritual they performed caused him to experience numerous potential futures, including those in which the Jedi triumphed over the Galactic Republic. He was also shown a vision of Darth Sidious, who would become his future Master.
The audio drama Dooku: Jedi Lost, written by Cavan Scott and released in 2019, marked the debut of death magic.