Nasus : Nerf his mid game, buff his late game.
Nasus is a very strong champion(obviously). So when it is almost impossible to stop him from farming his Q anyway, shouldn't it not be overpowered mid game? Then late game however, he completely falls off and can barely 2v1. I think Nasus should be nerfed during his mid game so he can 1v3 if he is fed and not be able to 1v5. Then his late game should be buffed so he can actually do something besides split push. In a teamfight, he is literally a 3.5 k health support. In 2 seconds he dies to any carry even if they don't have Last Whisper or Void Staff (respectively).
This probably would be good for both Nasus and his team and the opposing team. You probably could do any of the following to his mid game:
1.(Highly unrecommended, but possible) Make him gain 2 stacks per Q instead of 3. 2.(Maybe not the first part, but the second) Have his passive scale off his level to cap higher at level 18, but be lower or the same earlier (Helps with his late game too) and reduce the armor penetration on his E. 3.Increase his R power while tuning down his W and E, or make his W and E stronger when ulted and weaker when not. 4.Any other possible option.
Late game would probably be easier. Probably just give him bonus armor and/or magic resist when he ults. Maybe give his Q at rank 3 of his R armor penetration while ulting. I just think Nasus is too weak for teamfights late game. His tower pushing though is OP so the it would be best to not affect his Q that much.