Why the broken champs don't get nerfed.
etc.
They have zero diversity.
If you try to build anything but straight damage on Kat, you're going to get destroyed.
Riven doesn't even have AP scaling in her shield, where it is on most AD champs, and unlike most AD champs she can't be very effective with attack speed because she needs a burst, so all together you're at a big loss building even Trinity Force.
Vayne's going to be an ADC build every time you see her, unlike 
and 
.
Ahri is nothing but a mage. She won't be an ADC, her passive isn't strong enough to sustain in the jungle, and she can't build beefy enough to go top.
Zed, like Riven, has no AP scaling and relies on his burst. He can build Bork to fit with his passive but he doesn't have the sustain for more AS items.
There are other examples, and it may be even more of a problem when a champion can do several roles and builds effectively 
, but this is all I'm gonna type.
they nerfed her damage by 5 because her jungle was to strong which in turn makes her laning much harder or they "Gutted" AD fizz and put all the power in AP so he went from three lanes to one.
and 
