It's not even just the taunting. Having someone constantly in your face, constantly making you react, is mentally tiring. There aren't the normal breaks or lulls you get with most other fighters. Nick Diaz and Frankie Edgar created a new metagame within MMA striking, which is about consistent output, and Conor takes that to the next level. One thing that that makes him stand out from those two, in terms of striking, is his legit power in his hands. Conor has soul crushing power when he hits guys, you can see it in their eyes and actions after taking a shot. Robbie Lawler has that same kind of power. GGG has that same kind of power.