One aspect that I've noticed about Kyrie's defense when he is engaged is that he has to be one of the best blocking PGs in the league. Whenever he is engaged on defense, he blocks a lot of shots for a PG. I wouldn't be surprised to see him average .6+ blocks per game, which is great for a PG.
Kyrie has seemingly taken initiative in improving his defense, taking care of the ball, playing within an offense instead of being the offense like taking wise shots and playing well off the ball, and setting the tone for the game. Kyrie's intangibles look much, much better this season. It's stuff like this that is going to give Kyrie the chance to surpass the Chris Pauls and Stephen Currys of the league.