Calamity

Ardat-Yakshi (meaning 'Demon of the Night Winds' in an old forgotten dialect) is a rare genetic condition in vampiric dragons, specifically affecting their nervous systems. Although the condition does not harm the vampire, during mating the Ardat-Yakshi's nervous system completely overpowers and dominates that of their 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.