If you bully him hard early then he can’t really do anything.
My personal favorite for when I play against my main is Quinn, she has range to poke a lot early and have a very safe combo to receive almost no counter damage. You just poke him out at lvl 1 with e electrocute and some harrier proc, freeze the wave on your side of the map and zone him.
At lvl 6 you go roam to all of the other lanes and snowball those with a small advantage or help the losing lane and hopefully get a sweet bounty.
Against nasus in general, try to force him away from cannon minions, don’t let him stack those early. With the nasus buff they are even more important and letting him free farm cannons or minions in general will make it very hard for you to win against him.
The main weakness of nasus is that if he can’t get to you then he can’t hurt you (only applies to the regular nasus build and not full ap nasus/E max nasus), so if you keep him at range then he can’t get in range to q you. That was also why I suggested Quinn, you have your e to disrupt the nasus and put yourself at a safe distance, your q to give him nearsight so he can’t q you, flash to help get away is he gets too close after your combo, and ignite to deal true damage and with it grevious wounds to reduce Nasus’s innate healing.
For ADC’s one of the best counter pick options I can say is to lock in Vayne if you see a nasus. Vayne has a lot of anti nasus parts in her kit and item build. w to shred nasus, e to knock him back or stun if he hits a wall, q so Vayne can get away from nasus or to help chase the nasus, and her ult makes her go invisible (which makes it impossible for nasus to q her) when she uses q. Her first item is usually Bork which shreds nasus and other high hp champs. And if you want, as the adc you can request for your supp to go something like tahm, leona or an enchanter to protect you and/or CC lock the nasus.
I have a lot of comments about nasus, and I am a nasus main who knows what I am talking about. Please Read what I have said on other posts for more info on how to counter nasus, and I ask that any discussions from this comment should be kind, respectful and productive.
I can link an invite to the nasus mains discord if you want to ask them some questions or to discuss some stuff more with people who main nasus in high elo (plat and above)
