Will could say that he legitimately never expected to encounter someone of a similar mindset. To him, Zemo felt like the in-between both Hannibal and himself. There was not a lack of heart but a sense of control and intelligence. Will figured it would be unlikely that Zemo would entertain one of Hannibal's meals if he knew exactly what it was he was eating, but he would have an invite to the table out of comradery.
"A serum?" The blocks Will ran up against in the hotel when it came to his understanding of the special abilities of those around him was the fact that his own world did not have such extreme of things. His eyes traced the air thinking about it. "The issues you had were others like that?" He asked, picking up on the smallest shifts that lead him to the thought path.
"Some people think of it as such. My therapist called it 'Pure empathy' to my boss. I can assume the mindset of- anyone- know their motives, their past, their instincts..." He shrugged. "I recreated murders in my mind from the crime scenes I was sent to work and make connections no one else can."
His jaw jutted out briefly. "Nothing quite as fun as a government funded serum," he added sarcastically.