A light smile spread across his face.
When Ryu stepped into this world, he actually hadn't expected much. He had only come here for his wife, and after a few dared to have designs on her, he conveniently decided to also kill them.
However, after entering this sea, he realized just how special it was and he also saw an opportunity to allow his Dao to break free of the constraints of these Heavens.
As Ryu had deduced in the past, the Rotten Sea was akin to a proxy for the Heavens. It was using the main weakness of Demons—that being that they could be used as Summons—and turning it into a strength.
Everyone that entered was forced into suppression with this Seal, and by breaking through the layers of the Rotten Sea one after another, one could use that Seal as a proxy to strengthen themselves, or more accurately, their Bloodlines.