Growing up in the barrens isn't exactly easy for anyone, and it's worse for trolls trying to fit into the remains of a world too small for them. Fenris' childhood was spent struggling to survive in extreme poverty and homelessness - to this date he still remains SINless, not technically alive according to government records. It's an extremely dangerous way to live with few opportunities for success, with his only real choice being shadowrunning. He is a powerful adept and a skilled swordsman and makes most of his money hiring on to other runner groups as additional muscle; he prefers to keep his ties to others shallow.

It should be no surprise that he's gruff, short-tempered, and slow to trust most people. Most expect a stupid troll who's only good at fighting and really, that's all they get. Those who manage to get past his walls (which, really, aren't that thick to begin with) discover that he has a good sense of humour and can be quite charming when he wants to be. To these people he's an open book and wears his heart on his sleeve, but the slightest betrayal can bring his walls back down even harder than before.