Sian is a predatory alien symbiotic organism from the category of the Highest, which is obsessed with one specific goal-a chosen person.She looks like an attractive beautiful black-haired girl with purple eyes.She has a goal to become one with the chosen goal and this person is the only one who fits the parameters of his kind on the whole planet,because of the purely physical need for a combination of DNA,offspring and a connection at the cellular level of the symbiont with the chosen.