It's just that Lee Sin has a bit of everything and is good at it all. Displacement, reveal, damage, execute, sustain, shield, movement and attack speed slow, et cetera. If you have everything you therefore have no weaknesses and therefore there is no counterplay and it is a toxic champion. Yes his damage falls off late game but with his ability to kick people into his team, and provide AoE attack speed and movement speed slows going as high as 60% is a bit stupid, and if you DO build him with a fair amount of damage his completely insane ratios can destroy you. Being able to dominate the game completely and not give much if any chances for comebacks or stopping it because of 1 champion, regardless of how long you took learning it, is not something that should be allowed. Cough Kassadin.