Izek Strazni is a brutish tiefling who worked for the insane Burgomaster of Vallaki. Izek had one normal arm and one huge, demonic arm.
Izek was the one who decided to hang Diath for committing murder in Vallaki. Izek eventually realized that Strix was his sister and he was overjoyed. Strix was afraid of him. He helped her escape Lady Wachter's basement.