Seth has servants called Minions of Seth that do evil across the universe. Seth sees evil as a necessity to challenge good and keep good from getting to weighted on their end of the balance.
Seth is cruel and punishes minions for failing him, but offers great power to those who do well. Two notable minions decided their evil deeds would be to free Chaos and have been punished several times. They are Stormy Knight and Mr. Wicked (cousins).
Seth knows that Chaos cannot be freed, but will not strip the two cousins of their status because what they did was still irrefutably evil.
Links: True Gods