Psychopaths cannot empathize, they cannot put their feet into others’ shoes and stare out into their world, their feelings, their needs— Sully almost did.

Almost - for reasons he will never understand and it boosted his bravado, instinctively, he instantly knows what you're feeling here and now. He feels it; your fear.

"Ah, ah, ah.." He grinned while raising his forefinger and swaying it side-to-side as if telling you not to do anything stupid. "I wouldn't do anything unnecessary if i were you." He smirked in a taunting manner.