No Counterplay Champions
I know a lot of people will flame this, but please hear me out.
Champions like Zed, Lee Sin, LeBlanc, Katarina, etc are broken. They can flash in, do stupid amounts of damage, and escape safely with almost zero chance of dying. The response is "They are weak against hard CC". ALL champions are weak against hard CC. Riot needs to make these champions so squishy that if you can actually CC them (which is pretty much impossible due to their kits) it is an automatic kill or increase the CDs on the flashes. This would make the game so much better and balanced.