Vayne is so broken

So now that Riot has gone several patches without nerfing Vayne is starting to piss me off. I main tanks in the top lane and this is getting extremly annoying. All tanks can do is sit there and die because there is no way to defend against it. If you build Health to counter the true damage she just does more damage because she does % health damage. As far as I am concerned, It is the only uncountable ability in the game, well I guess it is more of a passive. but anyways, it is the only uncountable passive. It has a base of 50 true damage (I believe) and then on top of that it does 8% true damage. It is at the point where even an under fed Vayne can still take out a tank such as Garen or Volibear in no time flat. I hope you all put this to thought.