Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
Why Kartus tank? If you play teamplay you must help you or help you deal for a lot of kill.
Failure of the bulding is that you have no life not armor but in the end game for the last teamfigth you went to your team to be focused and you combine that closely monitored.
Logically you focus be gone by another enemy and die. Once a mass death you go hang déguat 7 seconds.