Rowan could not hold Oblivion in his heart and even now it was hard for him to recognize it, but he had learned to detect its traces after all these years.
Oblivion was a sneaky force, its very nature making it impossible for anyone to truly grasp and if Rowan was struggling, then it meant the average immortal had no hope of understanding this particular force and detecting its presence in their lives, and it had taken Rowan a long time to find the method to detect its traces including taking great extremely great risks in finding the Oblivion Gates and going as close as he could to it in order to learn more about its traits.
The Primordial Chaos was bound beside the Oblivion Gates, and Rowan could hear the clanking of the chains used in bounding Chaos, and even from an incredible distance, he still felt fear.