Remember when Champions were simple?
Had simple kits, simple numbers, were easy to balance by ratios and not mechanics or kit design? Back in the day we had champions like Ezreal, Cho'Gath, Garen. Now you have champions like Yasuo, Azir, Kalista, etc that all have in my opinion overloaded kits that make them very hard to balance because of said kit.
So back in the day you could nerf a champions base damages or ratios and it probably wouldn't hurt them too bad. But now you have to take into account all these different possibilities or outcomes of said nerfs. Like Azir's W damage. They nerfed it and it completely threw him into the gutter because of how it interacts with the rest of his kit.
TL;DR Just my two cents
as well

. Sure, they might be difficult to play correctly (Like old champs such as
. Was OP because he has so many tools in his kit. It took them basically an entire season to bring him down to a reasonable level.
right now. Doing something like removing the double crit portion of his passive might go a long way towards making him more fun to play against.
only has a few tricks, but he hasn't been difficult to get into a good spot since I've been playing so far as I know. He probably just needs his AP ratios buffed a little to compensate for the item changes, I think.