Maybe, just maybe, the villain's plan was to make Lucaon let his guard down or fall in love with Kyon. And knowing Kyon's attitude, he knew that once he remembered his purpose for being there that Kyon would run away. With that Lucaon would be so distracted by Kyon's sudden disappaerance that that would be the time to go for the kill or make do plan, whatever it is.
The ring disappeared(⊙…⊙ )