Before starting the battle, he showed respect to make Lia believe that he was going to fight a close-range battle, and then he used his words to say that he had seen through Lia's ability and that he was going to use tricks.
The purpose was to make Lia and Kai think that Rahn was going to use the same feinting tactics as those sand arrows like before and even that mud was part of the strategy to make Lia think that the attack was his way of tricking her.
But in reality, everything was just a lie!
His real move was actually brewing far above in the sky, and all he needed was for Lia to focus completely on him and ignore anything else!
This way her prediction ability got stuck on one target, which was him, and to prevent Kai from detecting the attack, he even used his pseudo-legendary skill to hide the attack's presence!
If Kai had enough mana supply from Lia, he might have been able to still sense the attack beforehand, but in the current situation, it was impossible.
