Hello guys this is unfazed and today I'm presenting you with a comprehensive guide for Nasus, the curator of the sands. Let's not waste any time!

Nasus' passive is soul eater, which grants him free lifesteal. This will help you survive your weak early game.
His q is Siphoning Strike which empowers your next basic attack. If you kill an enemy unit with your q, it's power is increased permanently. THIS IS WHY YOU WILL ALWAYS KILL MINIONS WITH Q. MAX IT FIRST SO IT HAS LESS COOLDOWN AND MORE DAMAGE.
His w is Wither which slows an enemy champion's movement and attack speed.
His e is Spirit Fire which deals damage over time and reduces the armor of enemies inside of it.
His ultimate is Fury of the Sands which grants him health while also deal damage to those around you.

PROS
+ Doesn't need any damage items
+ One of the strongest champions late game
+ natural sustain
+ Great area damage

CONS
- Weak early game
- farm reliant
- not any cc

Start with Doran's Shield and a Health Potion so you can last longer in lane. When you get back to base, get a Sheen if you are winning your lane, or Aegis of the Legion if you are losing. For boots get Ninja Tabi against ad or Mercury's Treads against ap. You can also get Boots of Swiftness but you won't be tanky at all. Choose between Iceborn Gauntlet and Trinity Force, based on what your team needs. If you are the only tank, then go with the gauntlet. Get a Spirit Visage for some mr, hp, cooldown and the healing boost. Get a Warmog's Armor for massive hp, and finish your build with Randuin's Omen. The enemy team will sure have a hard time against you.

I usually go with Ghost and Teleport. Ghost helps you chase down enemies, works well with your w, can help you escape and has low cooldown. Teleport can be used mostly to return to your lane and keep farming, or for a devastating gank at bottom lane.
Flash can be a nice choice too, always saves us.
Ignite can deal some extra damage and secure kills, but I think teleport will be more useful.
Exhaust is such a nice spell for 1vs1, if you decide to pick it,don't use it at the same time with Wither, wait for one to end and then use the other.

As everybody knows, Nasus relies on farming minions with his Siphoning Strike, so your enemies will do everything to deny farm to you. They will keep harassing you so you lose minions. You must be aware of that, and do everything you can to avoid it. Don't stay close to your enemy so he can't reach you. Farm a dying minion with your q and then immediately back off. Don't push the creeps, let the enemy push instead. You will be farming peacefully near your turret while also you may get a gank from your jungler. If you accidentaly pushed your lane or the enemy is missing, don't overextend, go to your jungle and farm monsters.

All in all guys, I believe Nasus is one of the toughest champions in league of legends. You don't need to get fed, just keep farming like a maniac, farm, farm and only farm. At around 200 stacks on q, you will be able to eliminate your enemy in no time. That's all guys I hope you find this useful, if you have any question please just ask :)