Sanguine Magic

Vampiric or Sanguine Spellwork, commonly known as Blood Magic is, like Elsebringing, a kind of subcategory of Ceremony. However where Elsebringing is defined by its goals and effects, that being the summoning of otherworldly creatures, Blood Magic is concerned with the source. Any sort of magic which trades in life for power is considered sanguine. The purpose that power is used for is irrelevant for its categorization.

Despite the crude sounding name, it is not as evil of a subset of spells as that might suggest. Plenty of spells use life as barter, including Elsebringing rituals and protection spells. However it is true that most spells which deal with vaster quantities of magic sourced from vampiric means is rather nefarious in nature.