An aspiring Starfleet counsellor, Deanna Troi is half Betazoid and half Human, and has extra-sensory empathy, giving her a keen insight into the emotional state of those around her. However, her ability is limited when it comes to beings with different brain structures to Humans and Betazoids, and so she spends as much time as she can studying the psychology of unfamiliar species. Having suffered through tragedy at an early age from the loss of her sister, Troi chose to dedicate her life to helping others through loss and trauma, and help heal those who have suffered emotional damage. With an unmatched sense of compassion, and a penchant for quick thinking and decision making, Troi can be a tremendous asset for Starfleet.