Upon successfully ascending to the Sovereign Realm, the Aura Sea within a person would be shattered and replaced with the Sovereign Sea. Shattering the Aura Sea and forming the Sovereign Sea.
The Sovereign Sea is more complete and robust compared to the Aura Sea. Although the Aura Sea existed in the body and essential to cultivators, it is also the weakest. The moment the Aura Sea is destroyed, then their path in cultivation would come to an end, and all their hard work in cultivation would be for nought. As for the Sovereign Sea, it is incredibly profound. Not only it purely exist in the human body, it also forms a profound small world. The small world is concealed in the body; thus, compared to the Aura Sea, it is more mysterious, more significant and more powerful. The toughness of it is something that the Aura Sea could never be compared to.
Furthermore, the most critical point is that the instant the Sovereign Sea is formed, it could be concealed in the cultivator's Spirit. Thus, even if their physical body is destroyed, as long as their Spirit and Sovereign Sea still exists, it is just a matter of time before they could refine another physical body.