When you come out into the Domain of Secrets, get close to Keeper Kauniss and he will begin a slow march around the Margonite temple in the area. He will stop in the middle of the temple and perform his quick incantation. At that point, a large group of Skiro'ken Assassins will appear in the middle of the temple. You no longer have to keep Keeper Kauniss alive after he does his incantation, but you do have to speak to him to get the reward. That means you will have to take out the newly appeared group of Skiro'ken Assassins.