Spent his life in the poor part of the city most of time, got beat down by rich kids and middle class kids. Developed anti social behavior, start dedicating himself to the art of combat, his dad teaches him how to use a bow and a sword, the rest the kid got by himself.
Ended up being a bounty hunter, now him and his family have a better life since he knows how to track his bounties.
Father is an ex debilitated soldier, lost his left foot in combat, damn warhammers he always said.Likes to drink, but have a good heart, wants the kid to succeed.
His mother is just a cook for the local tavern, at least made Sebastian endure his harsh childhood with her maternal support.Worries too much but kept to herself, fear that the kid might go to the contract killer path.