Why is Kayn so op

Why does a champ with no passive for 15+ min that is easily countered if you shut them down early so op. I mean it's so hard to shut someone down in the early game am I right. Especially a jungler who has to trust his laners to not screw up. I mean rito why have a heal when he enters a wall. It's just unnecessary even though every other jungler has some sort of way to heal? While I'm on the topic of being in a wall it just makes him so op. Even though I have a huge indicator to see that he's coming. I think we should add a huge warning label that pops up when he is within 1000 range of us that way he can't surprise gank us when we are pushed too far up. Also his w is op. A 1 second nock up on a bruiser. It's not like any other bruisers have nock ups ( cough cough Darius cough cough )

To conclude plz nerf this op champ rito he is just too good