Blood Mage (Origins)

A blood mage is a mage who employs dark rites, originally taught to mortals by demons, in order to access more powerful magic. A blood mage must be willing to sacrifice his own life force or that of others in order to wield this power. Blood mage is one of the mage specializations in Dragon Age: Origins, Dragon Age: Origins - Awakening, and revealed to be in Dragon Age II.

Blood Magic in Thedas
Blood magic was the first form of magic on Thedas. According to legend, it was taught to Archon Thalsian, founder of the Tevinter Imperium, by Dumat, The Old God of Silence. Historians argue on this point, suggesting the Imperium's mages may have learned it from the elves of Arlathan. Whatever its origin, Blood Magic was used by the magisters of the Tevinter Imperium to rule over the whole of Thedas. According to the Chantry, its reckless use eventually led to the blackening of the Golden City, the creation of the darkspawn, and the first Blight.

In the contemporary world, blood magic is described as being one of the more "sinister" types of magic. Blood magic is the magical practice of using blood, life itself, as a potent fuel for magical spells. This life may be supplied by the mage, or by willing or unwilling sacrifices. It lets the mage control the minds of others as well as use their very own life force to fuel their power. This practice is so rare in Thedas now that it can now only be learned from contacting a demon, with the risk of becoming an abomination.

The Chantry strictly forbids the usage of blood magic as it supposedly eventually leads to corruption. Mages using blood magic are labeled maleficars and hunted by the Order of Templars, an order created for the purpose of controlling mages, killing demons and, more specifically, for hunting down maleficars and apostates. Indeed, the Chantry seems almost irrational in its fear of Blood Magic; going so far as to suppress anatomical study and ignoring more immediate or severe threats. The Circle of Magi endeavors to supervise all magic-sensitive people from a young age and ensure none of them tap into this forbidden school of the arcane. However, even their constant supervision allows the occasional maleficar to slip through their fingers and out into the world.

Blood Magic and the Grey Wardens
Despite blood magic being banned in Ferelden, the Grey Wardens occasionally use it as a means to fight the darkspawn. This is confirmed if the Warden speaks with Duncan on the topic during the Mage Origin.

In the Warden's Keep DLC, an ancient Grey Warden mage called Avernus had utilized blood magic to manipulate the darkspawn taint used in the Joining. He even went so far as to torture his fellow Wardens in order to learn the secret powers found within the blood while theorizing the extensive capabilities it holds and stating that only within the ranks of the Grey Wardens can blood magic be used freely and allowed to flourish in the name of arcane progress. What he learned allowed him to use blood magic to survive unnaturally for hundreds of years as well as discover powerful talents and spells that the Warden can choose to use to unlock the Power of Blood school. Avernus argues that the Chantry foolishly forbids blood magic because of their belief that it caused the corruption of the Golden City (which he dismisses as lies) and that there is a great deal that the Grey Wardens, and mages in general, can learn from it.

Unlocking
During the Arl of Redcliffe quest line, if the Warden is a mage, there will be an opportunity to unlock the specialization by choosing to enter the Fade to kill the Desire Demon. You must use the Warden and you must be a mage to enter the fade, no other character/class-type can unlock it (if you free Jowan when you enter the secret passage to the castle, he can help you with entering the fade). When you reach the end of the Fade, you'll meet up with the true form of the Desire Demon and will be given the option to talk with her or fight her. If you elect to converse with her and strike a deal, one of the rewards available is the Blood Mage specialization. Also, if you do decide to go this route, rest assured that nothing changes in terms of story, and the results are exactly the same as they would be if you elected to kill the demon - that is, until the epilogue which will reveal a different fate for the boy Connor. For full details and the dialog options you can all pick. (See Arl of Redcliffe for complete dialogue.)

Additionally, it can be unlocked in Dragon Age: Origins - Awakening by purchasing the manual from the bartender at The Crown and Lion tavern in the City of Amaranthine.

Blood mage items
(Obtained by completing four on the side proving matches in Orzammar, given by the proving armsmaster.) (Looted from Avernus at the end of the Warden's Keep DLC) (Inside an egg in Wyrmling Lair during Urn of Sacred Ashes Quest) (Located in an armoire during the Freedom for Anders quest in the Awakening expansion) (Appears in inventory after completing The Golems of Amgarrak)

Notable blood mages

 * The Magisters of the Imperium
 * Jowan
 * Avernus
 * Caladrius
 * Zathrian
 * Mad Hermit
 * The Baroness
 * Uldred (though it is also possible that he only sought the help of blood mages, and was not a blood mage himself)
 * The Warden (Blood Mage specialization)
 * Merrill (Dragon Age II)
 * Hawke (CGI Hawke is a Blood Mage)

Links
Blood Magic Guide on Gamefaqs

PC Games preview