Talk:Karthus/@comment-99.43.165.61-20120617022934/@comment-77.236.25.91-20120617122600

The main reason why he can be banned is (at least I guess so) that he deals enormous amount of damage in teamfights and is able to help other lanes without leaving mid and losing farm. His ulti helps him mainly in early snowballing, in late game he doesnt necessarily need to kill with R if he did it correctly earlier.

Also, good Karthus is able to land kills with R despite enemy Soraka, banshees, and a lot of other things. Zhonya is indeed extremely hard to break through, but fortunately only a few champs can synergize with this item well enough. Still, there is no way to really "counter" Karthus - you can make his life harder or you can just outplay him, but there is no champion or item that would grant you a free win against skilled karth.