Stefan is the joker of the group. He is able to mimic sounds and voices perfectly and uses his wits to poke fun at people who are pompous and cruel, such as Tursgud. This skill is used multiple times in multiple training exercises and battles to confuse the brotherband's enemies. He will not crack jokes about people who are weaker than him, aiming only at those who are stronger, with bad personalities. He admires Hal Mikkelson for his skills.
He isn't a good fighter at all, he is like Edvin, but, his abilities helped the Herons in the book 1, the outcasts, when they were trying to invade the Sharks brotherhood house, then, Stefan made a good of a mess, he used the voice of Tursgud and confuse all the sharks.
In book 5, he uses his mimicking ability to confuse the men from one of the Ishti rafts when they advance on Lydia, armed only with her dirk.
Stefan is one of the sail handlers on the Heron.