Qareen are a type of creature, similar to a genie, that can be controlled to do the bidding of a master, who is in possession of their heart. Qareens are shapeshifters and will take on the form of a person's deepest, darkest desire to seduce and then kill the victim. The only way to kill a qareen is by stabbing its heart. Based from notes in Sonja's lore book, their existence was known since ancient Aramaean and Arabian era. And the lore book itself, was written in old Arabian text.