I can't help but correct this: Lee Sin, Kayn or Karthus are not Counters to Yi. And Elise? Not even close if you can time your Q. If you ran Conqueror vs Champs that build Thornmail you wouldn't have a problem dying to them either and "Can´t gank pre level 6" .. really? i mean.. really?? You have a massive gap close and dodge ability with your Q!

In my personal Opinion building BotRk before Guinsoos, building BT in general instead of Death´s Dance or building IE without another Crit item should be bannable and punishable by snu snu.
Furthermore, Conqueror is the more consistent way against any Bruiser and UDYR IS NOT A COUNTER LMAO