After Corpse Sea got the Life Seal, he was like an enraged beast turning into a nice lamb. The Life Seal was changing his body, adjusting his chaotic conscious and waking him from the realm of insanity.
If a beast could calm down and reason with human intellect, its intimidating features would be enhanced incredibly.
Everybody knew that.
Corpse Sea’s change made Tang Yuan Nan, and Ouyang Luo Shang astounded. The Life Seal Shi Yan had performed was mysterious beyond anything they had ever seen before. This sort of a martial technique didn't belong to the Three Gods Sect, neither the Yangs. This shocked and frightened the two a lot.
As for the doubts of these two, Shi Yan didn’t want to explain. He just smiled and watched Corpse Sea.