Nasus is problematic. Lets look to Paragon for help.

I just feel that nasus is a bad mechanic for league. Infinite stacking on any champ can be really frustrating to play against. The main problem is that they are able to achieve terrifying levels of damage without actually building damage. I had for a long time thought that nasus was annoying but honestly balanced, but with the changes to itemization and lethality tanks are being increasingly difficult to take down. I just played a game against a nasus that didnt build a single damage item. the closest item to a damage item they had was Iceborn Gauntlet. Funny thing. He out damaged his whole team.

Instead of just gutting him like a lot of people want to do i want to implement what paragon did with Severog. Severog gains his increased q damage at stack intervals. So in Nasus's case instead of 500 stacks = 500 bonus damage, 500 stacks = Tier 5 of his Q which comes out to 250 bonus damage. Each tier could be at 100 stacks and caps at 500. Also he can get another stat on his tiers to make up for the loss of his one shot potential. so at 500 stacks he will get 250 bonus Q damage as well as 25 armor and magic resist +500 hp. This will move him more towards being a tanky bruiser instead of an unkillable juggernaut of doom who one shots you without any damage items

Also on a side note. Tank veig is horrifying. If you havent played it, try it. its fucking dumb. you just farm for 30 min and then build full tank and you literally cant die and can still one shot people.