Blood rage is a genetic illness that affects vampires. Blood rage can cause loss of control and violent impulses. It may be triggered by strong emotion, such as rage or fear. It also has the surprising characteristic of making a male vampire potentially able to father children biologically with certain types of female witches called weavers.
Vampires suffering from blood rage have sometimes been able to develop more control over their symptoms over time, especially when provided a supportive environment.
Blood rage is a triggered genetic disease that comes from a vampire changing a creature with any amount of daemonioc DNA present in their genetic make-up. That is, a daemon that is changed to a vampire or a human whom has daemonic DNA present in their blood.
It is not stated as to how a witch with daemonic DNA in their blood will react to the change, seeing a witch with daemonic DNA is a Weaver, a special type of witch that is capable of bearing children with a vampire who has blood rage.
Prior to the events of The Book of Life, any vampire known or suspected to be suffering from blood rage would be put down, along with their sire and children. Blood rage was viewed as uncontrollable, leading to the view that the only way to deal with the problem was to eliminate all affected vampires.
Blood rage is a result of a creature whom has some quantity, mintue or not, of daemon blood in them. If a full deamon were to have been turned into a vampire, then this vampire would in turn have blood rage. This is true in the case of Gerbert of Aurillac who turned his daemonic lover into a vampire, and whom he hid away for she developed blood rage. In the case of Matthew Clairmont and his grandson Jack Blackfrairs, both had some sort of daemonic dna in their DNA, through some past ancestor, which the cause of blood rage being displayed.
Connection to Weavers:Edit
The reason a vampire with blood rage and a weaver is able to concieve children is because weavers are witches whom also have daemonic strands of DNA within their genetic makeup. Because both cretaures share this genetic makup, and both of these creatures also have the 24-pair chromosomes, they have the ability to concieve children with one another. Nathaniel and Sophie Wilson's daughter Margaret Wilson, whose daemon mother was born from witches, and whose father is a daemon, will thus be a weaver like Diana Bishop-Clairmont.
Gerbert of Aurillac's unnamed Lover