Adrian could clearly see that this person dressed in monk robes in front of him is different. He is sure that this monk can sense his power levels but is not scared of him. Adrian then wondered if some of the wuxia novels he read about people being respectful to you as long as you are powerful actually true.
Another idea would be that despite the monk being weaker than Adrian, the monk is confident enough to defeat Adrian or escape. Adrian bet that it is the latter as the old monk's vision did not stay on him but looking at his surroundings. Adrian wanted to be sure so he activated his evil eyes but he felt a backlash.
"This has never happened before because Evil Eye is an epic ocular skill. Unless he has an item that can reflect ocular skill then that it makes it difficult." Adrian stated as he tried using it again but this time he used Soul Essence to empower the skill.