Cain's Ego Wave invaded the Wave King, and the fear within this one was so immense that he could put the man into hypnosis without a problem. It was only then that he turned toward Farius, using his Ego Wave to monitor the man's heart rate and brainwaves.
While the most effective path would have been to hypnotize Farius as well, Cain was not confident in his ability to forcefully compel a Middle Wave King, and he could not afford to suffer a backlash.
Instead of hypnotizing Farius, Cain planned to monitor this one's vitals to detect any lies and would use Timothy and the Early Wave King to fill in the blanks.
"Answer my question honestly and thoroughly, or else you will end up like him."
Farius knew he needed to maintain a strong front if he wanted to survive, but the fear was too much. The idea of lying faded from his mind when he saw the other two being hypnotized since they might uncover his farce.
