You want the wave on your side of the turret pre six so you can run him down early game. Post six you also want the wave on your side so he cannot run you down with ult and you can safely bait his wither. Try not to push the wave when you are farming or poking with q.

3Q>E Max Go Doran’sShield against him if he has aery otherwise go Doran’sBlade. Ignite is viable PTA is also viable Try to bait out his w and hard trade when it is down. Track his jungler so you do not get ganked pre six. Swiftness boots are recommended.

Short trades against nasus are not favored since Nasus has a high amount of sustain with his passive and often buys sheen. Utilizing your lethal tempo and passive auto damage to take extended fights is key to winning trades. You have to do enough damage to him in long trades that your e active auto does enough damage to really pressure him off the wave. When you are both six, you have to play to bait out his wither. Whenever his wither is down you do a significant amount of damage to him whenever your lethal tempo stacks are up.