Hemoturgy

The act of using blood as a catalyst or force of magic. A reviled craft for the actions taken in its study, most practitioners typically taking such actions too far and becoming monsters of blood-letting and sacrificing innocent lives in search of a deeper research or power. 
This study comes from the Blood Elves, as most sanguine arts do, though they claim it originally came from vampires and that they were given a more refined, studious version by Kashil. The version stolen from vampires was a vicious tearing of lifeforce and blood. 
The term Hemoturgy is a catch-all to spells and even powers utilizing blood as a focus or strength. Hemomancers are more specified towards spellcasters. However, there have been claims of blood elves drawing blood on blades and having it be lit aflame magically or freezing and being flung as additional weapons. Either way most do not find engaging in combat against a blood elf in the Stained Weald to be a wise idea due to the variety and sheer amount of blood there. It rains from the heavens and seeps from the earth. Every which way you might look comes some form of crimson, leaking out in odd vein-like systems.