I highly recommend you try this build before rating it.

This is a very unorthodox Nasus build, but it's without a doubt sleeper OP. Essentially, you spam E in the early game to poke your opponent to death, or force them out of lane. The purpose of this build is to sacrifice lategame runes (such as conq, legend tenacity etc) for raw early game power. Traditionally, Nasus is the champ that gets punished hard early, but if he survives til late he can end the game by himself. This build setup allows you to completely stomp most champs in the early game, in order to guarantee you get your items on time (and you will end up solo-killing your lane opponent a LOT if they don't play smart against you).

By taking Comet + Scorch + double adaptive minor runes + Doran's ring, your E does absurdly high damage and will basically oneshot minion waves from level 1 to level 11, allowing you to hard shove. This forces your lane opponent to take minion aggro while CSing, or farm under turret where they will lose CS because of your E poke. They will either be forced to recall, or die under turret.

The downside to this is that Q-stacking is harder to do early, because your rank 1 Q has a very long cooldown. This tradeoff is worth it. Traditional Q-max builds tend to get bullied out of lane really easily. A few extra stacks on Q is NOT WORTH being 40-50 CS down. By hard winning the early game, you opponent won't have any pressure on you during the midgame, allowing you to stack Qs freely.

In the midgame you have great lane priority. Look to make TP plays to snowball your other lanes. During the midgame, you'll be transitioning to a more traditional build, i.e. Triforce and Righteous Glory. Your lane opponent will be down in CS and items, allowing you to stack Q freely. If your lead is large enough, it could be worth freezing the wave under your tower (and running down your opponent with W if they overextend) if you can set this up. The one downside to E-max Nasus is the threat of enemy jungle ganks when you shove the wave. Try to get deep wards in the enemy jungle.

In the lategame, you play Nasus the traditional way - split push whenever you have vision of the enemy team, or when a big objective is up. Thanks to your huge early-game lead, the enemy toplaner can't answer your split-push. If you have good map awareness, you can end the game solo like any other lategame Nasus.