Blood magic

Magic that deals with the manipulation of a person’s life force, usually using the target’s blood as a proxy. Ritual sacrifice, powering spells through one’s own health, improved enhancement rituals and bloodline theft are all accomplished through blood magic.

Life force is a very potent form of mana, useful for a lot of things. Unlike spending mana, however, spending one’s life force is a pretty big deal – life force recovers extremely slowly and the body will not easily relinquish it to the caster. It must be coaxed or forced into allowing it, and no matter the method used it will result in lasting weakening and sickness that will persist for days or even weeks. Vertigo, exhaustion, lethargy and phantom pains are all typical consequences of life force depletion. Additionally, while losing a little life force from time to time will not permanently affect a person, dipping into one’s life force too deeply or too often will inflict permanent consequences… and it’s hard to know where exactly the limit lies.

All of this means that blood mages dislike using their own life force as a rule, and instead focus on stealing it from others. And this stolen life force is usually used for demon summoning. Because of that, blood magic is very, very illegal – easily on par with soul magic, if not worse. Most countries deliberately suppress information about blood magic, other than warning people that it’s bad and they should never use it. Despite that, the field refuses to die out.^[1]

Zorian gets some information about blood magic from Kael^[2], and then from stolen cultist texts^[3]. Zorian classified the use of blood magic magic as follows^[3]:

• Tapping your own life force to cast spells. Zorian compares it favorably to drawing on un-assimilated ambient mana (especially so inside the time loop); it's more likely to be fatal, but will have no impact on sanity. Two cases of using as much as possible life force (killing the user) is shown in the story: by an unnamed Ibasan mage^[4] and by Daimen^[5]. Xvim, Zorian himself and Zach use it once for a limited extent^[5].

• Killing other people to extract and use their life force. This can be bargained away with demons or used in special rituals, since life force is very potent, but it's quite difficult to shape someone else's life force directly.

• Enhancement rituals, allowing people to gain permanent magical abilities at the cost of permanently occupying a portion of their mana reserves. Enhancement rituals do not have to involve blood magic, but incorporating it allows them to be better integrated into the target, reducing the cost and potentially turning them into inheritable bloodlines.