Is that supposed to be "poise and demeanor", when describing JJ. Maybe "poison demeanor" is some slang with which I'm not familiar, because I'm old.
https://www.espn.com/college-football/story/_/id/35328803/michigan-hoping-avoid-regret-last-year-cfp-loss
"He is just more confident," co-offensive coordinator Sherrone Moore said. "He always had the same poison demeanor, but you can just see him grow in his decision making and the way he takes care of the ball and the way he runs and does things that he does to help us to win."