Lee sin is a very dumb champion. The fact that his ultimate is on a 33 second cooldown once you have maximum cooldown is insane. That means that he can use his ultimate twice in a teamfight. Also, his ultimate takes away his skill due to it's devastating base damage and ratios. You cannot miss your Q when you kicked someone in the spleen, the cc of his ultimate is unreal. His synergy with the trackers knife and deadmans is ridicilous. He can roam around the map in just a short amount of time with his very high base movement speed.
I would suggest to increase the cooldown of his ultimate and nerf his base movement speed.
When you almost outplay him but he R and Qs you