He dislikes anyone and refuses to disclose the location of his treasure, but may change his mind if someone else was in the same position as himself. If he gets killed the quest he is involved in cannot be completed. Also, as a side note, if the Hero attacks Jorundr while in the cell, the guard will open the cell door and attempt to break up the fight, but the guard attacks Jorundr, what could lead to his death but allowing the Hero to escape.
While roaming around the city of Bruma, the Hero can overhear rumors about Arnora Auria. According to the rumor mill, Auria's lover, Jorundr, has been arrested for stealing money from Auria. Auria reportedly needs help recovering the stolen money.