Jungle Diana
Jungle Diana needs HEAVY nerfs. This isn't a QQ post, even though I know all the Diana mains will say so. Just stating the facts.
I just finished a game where I COMPLETELY shut down their jungle Diana as Nunu. I took BOTH her red and blue buffs and she didn't get ANY of my jungle. She was about as far behind as you could possible set a jungler but she still goes 7/2/7. Despite having pretty much no gold or experience for the first 10 minutes of the game.
What good is it to dominate your opponent if they are just going to carry anyway? That is the problem with EVERY assassin in the game: low risk/high reward. If you are skilled enough to shut down one early, they should be literally worthless the entire game for taking an early power champion and not succeeding.