Taliesin left the Elven home world of Cangen along with his sister to deal with his unhealthy fascination with humans. Other species may wonder why leave the elven world with its relatively few humans for the wider galaxy with its far more humans, but such is elven logic. That was also why Brena booked them passage on a cheap ship registered to the dwarves.
Taliesin is an official assassin of the Dulcen government, though he does not wish to talk about it. It mostly means his wardrobe is filled with blacks and dark colors to blend in with shadows, he is very good if not more comfortable crawling through tight places and has different rules about what can be taken on board transport shuttles.