Items/bruiser/assassin champions. I don't think the champions them selfs are OP, but i think bruiser/assassin items are too easy to get without risk, and pretty strong. I mean i main kha, all i have to do is build BC, and can build tanky for the rest of the game. and i can still deal a wiener load of damage, same said for all other bruiser champions. We need a nerf on items such as BC, maybe not in stats. But on obtaining the BC, for example you can only buy straight brutalizer now, instead of two long swords before hand.
Hopefully you get where i am going with this. I can be pretty bad at explaning things haha