Lin Fei did not dwell on it for long anyway. Clearing the trials was not urgent, so since he had decided to try and obtain the Shark King Pearl, he would tackle that first.
Thus, he directly cast the Shape-Shifting Technique, transforming into the appearance of a merman as well, and then placed a barrier of isolation upon his body.
Given his proficiency in barrier arts, it certainly would not be easy for these mermen to easily see through him.
Chapter 1699