This has to be the dumbest thing they've done since last preseason.
Honestly, after playing a against COURAGE OF COLUSSUS RIVEN, i have no desire to play this game again until the mastery is removed.
I've never seen something more abused than this mastery. It completely broke the meta and balance of the game.
Ignoring how broken it is on champs that it wasn't even designed for (read: riven), it is not ok to have a 5k hp rammus with a 2k shield in teamfights.