What champ do you personally never see be useful?

Of course every champ in the game can be good (game is actually quite balanced) but there are some that I personally dread having on my team because they seem so useless.

For me its gotta be Rengar. Honestly what does that champ even do. If he gets ahead, sure, he can one shot squishies but often thats not enough to win the whole game. If he's behind, game over.