I will begin to ban Lee Sin, and that's not because he is "OP"...
...but because I don't want my allies to pick him.
Recently, all Lee Sins that I get on my team do lots of shits, they think that "insec wins games", die a lot and are more useless than a minion.
They are stupid and the skin they have is just for "display" because they have no skill whatsoever.
Just because you saw a champion being used on LCS, does not mean that you can take this champion and just imitate what the pro players did with him,
is not a good champion for SoloQ, he is extremely hard to master and requires deep communication with the team to cover his weakness, such as the fact that he falls off late game.