Threats to Nasus with this build
|Teemo||His blinds interfere with your stacking process which is frustrating as hell.|
The build above is used on the Twisted Treeline map, which also includes the Hexakill game mode, although I would NOT recommend going Jungle in general in Hexakill.
In the early game you may find may encounter some difficulty with timing your Q cooldown with executing jungle creeps; in that case, if the creeps are executable but your Q is on cooldown, simply walk away a bit and kite for a few seconds; even if you take damage while waiting, your Passive's bonus lifesteal will heal you anyway, not to mention you will have a Refillable Potion.
In the mid-game, while jungling, you may want to start with a Q proc on the large monster first; your Q can also one-shot the smaller creeps, so you may want to start with that or on your second Q proc. Invading the enemy jungle is also a viable option since most junglers on the Twisted Treeline can't fight Nasus 1v1, although you should be aware where the enemy laners are.
The great thing about Jungle Nasus on the Twisted Treeline is that by lategame, you're practically unkillable; your health regeneration, lifesteal, and Q damage make you a powerful bruiser, and most enemy champions would not dare engage in a 1v1. Remember to smite the Golems for their tower debuff for maximum lane shove for the lategame.