a) How do you know the Professor? How close was your relationship and for how long? Why do you think, he chose to think of you among the many hundreds that he had worked with or had known? (Meeting him abroad is well and good, regular correspondence is fine and its ok to make up your own reason for him favouring you)
The professor met Vigilance when he stumbled upon the tiefling's private investigation office he had just started renting with support from the Abadarian church. While the tiefling continued to work off and on for Lorrimor, studying secrets the academic didn't feel safe studying, his offices were burned down in an attempt to murder Vigilance and the tiefling has become more of a free agent around the country since.
b) Why are you in Ustalav? Do you live here? Are you studying? Visiting relatives? Doing research? What are you doing for a living – after all it costs money unless you have something else to provide you income. (Ideally, aim for a reason that will have you no more than 2-3 weeks travel from Ravengro).
Vigilance hunts information for those unable to do so. He looks to maintain justice in a country that seems to have given up on the idea.
c) What drives you? What are your passions and what are your goals?
A pursuit of justice and a civilized Ustalav.
d) What do you fear? What do you hate? Do you have any secrets? (Its ok to answer ‘nothing’ to some or all of these).
Fear: Nothing, but only really because he's so damaged that his sanity is really the only thing he has left keeping him human.
Hate: Injustice, barbarism, and boredom.
Secrets: He attempts to keep his tiefling heritage secret, but it's poorly kept.
e) What is your appearance and how do project yourself to others? How far removed from that is your self image.
Appearance: Vigilance dresses in the clothes of a sophisticate and academic. He wears a black, wide-brimmed hat to hide his horns at all times. He thinks of himself as a gentleman warrior, but his posture is always slightly off and his yellow eyes always a bit too focused. He looks like a man who is one bad night away from losing sanity and civilization and becoming the barbarian he loathes so much.
Finally come up with 2-3 personality quirks and a catch phrase or a habit if you can.
Personality quirk: He avoids pronouns and is the equivalent of a high-functioning autistic who has no use or understanding for human attachment outside of the rigid kind imposed by law.