Ardat-Yakshi

Ardat-Yakshi (meaning 'Demon of the Night Winds' in an old asari dialect) is a rare genetic condition in Asari, specifically affecting their nervous systems. Although the condition does not harm the asari, during mating the Ardat-Yakshi's nervous system completely overpowers and dominates that of her mate's, causing hemorrhaging in the victim's brain, and ultimately death in extreme cases. As a result, the Ardat-Yakshi becomes smarter, stronger, and deadlier after each encounter. Ardat-Yakshi also have the innate ability to dominate the minds of others. Falere, Rila and Morinth, all daughters of Samara, have the lethal version of this condition. Morinth chose to embrace her condition, while Falere and Rila opted for a life of peaceful seclusion. According to Samara, these are the only three living Ardat-Yakshi. However, less severe cases are supposedly more common, including up to 1% of the population.
The condition is impossible to identify until the asari reaches maturity, by which time it is too late to correct. When diagnosed, afflicted asari are given a choice: live in isolation or be executed. The asari do this to the Ardat-Yakshi because it is an addictive condition; they feel compelled to mate, and the compulsion grows stronger each time they succeed. While it is not known how much the Ardat-Yakshi's strength increases after each mating, or whether the victim makes any difference, Morinth's continuous use of her condition over centuries allowed her to match Samara's power and experience, despite the 500 year difference between them.
Ardat-Yakshi are a disgrace to the asari culture. It is suspected that this condition is what lies at the root of the asari prejudice against purebloods. Samara, a pureblood herself, states that the condition is as old as the asari species, and that it appears only among purebloods.
Morinth claims that the Ardat-Yakshi are the genetic destiny of the asari; a claim contradicted by the fact that all Ardat-Yakshi are sterile.

Genetic Ancestor(s)

• Asari