The new rework allows nasus to stack to easily. If he gets behind early game it doesn't take him out of the game. You can build stacks so fast. late game, give him a couple of minutes to farm a couple pushed lanes and he'll come back with 200 more stacks. CC helps when fighting a nasus, but if he stays with the team, you don't really want to target him because the enemy adc and mid will burst you down before you kill him. Too much famage for a tank champ imo. You either need to win the game very early, or if you have a top that shuts him down early game, you buy yourself a little more time, because he only gets stronger as the game goes on. He's like veigar except tanky and his big damage ability is a lower cool down and doesn't have a delay.