Since nasus is being the tumor of toplane again this is how you deal with him

You don't

Well more or less

You can never prevent him out scaling you

Therefore you want to do the following

Pick something which is better in teamfights Try and delay his ramp up as best as possible, this only works early on though, unless you completely roflstomp him early game then you can crash his Ramp up to the point he will never get relevant anymore Anyway while you delay his ramp up you can 100% expect jungler ganks early on since if they get the nasus ahead they wont ever have to deal with that lane again since he outscales his opponent anyway

As a jungler you can look to countergank here As a laner make sure to just gank midlane

Basically you want to get waveclear and shove him in he will stick to the wave and Q stack, big deal Meanwhile you go steal enemy jungle camps buffs if possible and gank mid all the time

Go to lane shove it in gank mid and steal jungle

Rather then dealing with nasus just deal with his team by making the enemy mid and jungler's lifes miserable If nasus keeps following you hurray he isn't stacking if he doesn't congrats you put 2 enemies behind and get your mid carry fed and your jungler ahead Either way you win If you also have a champ better at teamfighting then you win there too

All you need besides that is enough bulk to just hug turret and the waveclear so he cannot splitpush while your team wins for you

There is literally nothing that the stupid nasus can do about this all you need to know is that when fighting vs nasus you don't fight nasus but cripple his team instead because in the end it comes down to who has the stronger team, since nasus main thing is his outscaling splitpush and if your team is ahead this has like 0 impact and forces the nasus to help his team in which case you can use his own strategy against him, he can't really do the same early on because he needs those stacks to outscale you asap or his splitpush will fall flat

Because what nasus does best is afk push lane knowing nobody can fight him solo while his team is free to do whatever they want

All you need to do to deal with nasus is to get ahead of this and make it so your gets rolling first nasus lose 100% to this since there isn't anything he can do about it besides sacrifice his main strength which would make him kinda useless and he would lose because of that this literally takes all the fun out of it for the nasus and hopefully the guy will stop pestering people with him

Ofc there will be these times where you get stuck with a bunch of potatoes in that case just wait in fountain because the nasus won by default in which case the only play left is to also take the fun out of it for the nasus which is a dick move i know but sometimes dick moves are needed to deal with dick champs

In the if you follow this advice no nasus will ever have fun playing nasus again and he will probably end up getting reworked into something more tolerable to lane against since his playrate will drop below nonexistance

Sincerely someone who dislikes playing vs nasus