I thought what Arawn was trying to allude to is that what he is depends entirely on one's point of view. To the Empire, who became a force of power in this current world, he is a demon. He may lead to their destruction, and as the dominant force, that would be "the end of their world."

To others in the past, he was a king, and a savior. He seems to simply lead to the upheaval of the dominant power, ending their eras each time. The flashback of his previous death showed him fighting off something that we would think was a demon.