During Shael's severe injury, Shadow Sin found the Dark Goddess and helped Her regain strength.
The reason was simple, the Dark Goddess and Shadow Sin both desired to plunge the world back into shadows and chaos, hoping to establish a world devoid of sunlight.
This allowed Shael to catch his breath; otherwise, he would have been thoroughly dealt with by Serene.
However, in the end, Shael was unable to fulfill his promise and failed to plunge the world back into chaotic shadows. Later, the Lesser God Azus of the Magic Goddess devised a trap that captured a large number of Shadow Sins, and Shael, fearing the power of the Magic Goddess, did not intervene to rescue them.
By now, the Shadow Sin has become an endangered species.
Although Shael cannot exactly be said to have betrayed the Shadow Sin, he definitely owes them a lot.
Therefore, Shael never expected that, when he found himself weakened once again, the Poet would come to his door to help him once more.
