Nasus needs another kind of change
Nasus doesn't need more damage, Rito. He has a really High damage output already. Nasus needs more tools to teamfight. He is too slow, predictable and easy to target... He doesn't have any tools to protect himself of CC, Wither isn't really effective against peeling like a Darius pull or Illaoi ult, his tankiness isn't amplified in teamfights and he doesn't have a effective way to engage a teamfight... That's what make Nasus weak from my point of view. You will give him the wrong kind of buff (E and R buff) and he will end up being toxic.