An alchemist who made a great mistake--and paid dearly for it
Despite her appearance, Tali feels all the emotions anyone else would feel--happiness, sadness, love, hate: she is not the emotionless automaton everyone perceives her to be. She is simply unable to show any emotion whatsoever--the circumstances of this are detailed below. Had she been able to express herself, one would find her to be a cool, calm, collected but friendly young woman--but due to her 'curse' all anyone sees of Tali is an apathetic, almost robotic soul.
Tali Visneia was born in Central City to a man who worked as a State Alchemist, and was prepared to educate his daughter in secrecy on the ways of alchemy before she would be sent for an 'official' education of how to use her power. He taught her much about the art of alchemy, but he could not complete her 'education'; on an assignment, this state alchemist, Tali's father, disappeared, and after four years was taken to have been killed. Despite this, even at a young age, Tali always had a strange feeling that her father was truly alive somewhere, and, determined to carry on her education--being that she was too young still for an official education--on her own. Managing to keep her practice secret, she continued to hone her skills in alchemy up until she could enter the test to become a state alchemist at eighteen.
It was that very year that her entire life changed, for better or for worse. She had just passed the test, and was well on her way to becoming a state alchemist--but she was not satisfied, not convinced it was enough for her to do what she had always been planning to do--go after her father. She chose instead to enhance her power using something of a 'shortcut'--she wished to grant herself the gift of wisdom using alchemy; it required a highly complex and dangerous alchemical ritual. Deciding to foolishly attempt the ritual anyway--so excited that this ritual would grant her the ability to find her father that she entirely ignored or failed to see the risks--Tali attempted the ritual.
Ultimately, the ritual was successful--at a great cost. The first thing Tali noticed was that she could suddenly gain insights, feel 'hints' as to what objective she was pursuing at the time. But it was very soon after that she realised that she could not express her joy; she could not display feeling or emotion. The ability to smile, laugh, cry, speak sarcastically, glare, it had all been removed from her. While inside she was exploding with feelings and emotions, on the outside there was only nothingness.
It was some time afterwards that the second consequence presented itself: Tali was fading. In other words, dying. It was a long, gradual process to which there was no cure, no treatment, no healing; not even alchemy could prevent it. The other state alchemists estimate that she has only another year left to live; though they had hoped to keep it secret, it is general knowledge that the apparently unfeeling, apathetic Tali Visneia had only twelve months to live.
Now she works, when not on missions, aiding those taking the entrance exams into the state alchemist group. She offers one bit of advise in particular: Never overestimate your alchemical powers, or risk deadly consequences.