Well. My first guide. I love Nasus because of that availability of oneshoting your ACD even if he is full tank. And every single enemy complaining about your damage and calling you a noobchamp just because you only have to press 2 keys and you get a kill. That is what this guide is all about. Let's start.

You can take demolish for split pushing since you can almost oneshot turrets. You can take font of life, but its not good because you only slow one at a time. Second wind is the best for more sustain and its a great rune when its comboed with doran's shield. conditioning is good, but it doesnt give you early sustain, you can take it for late game. In this path the one I should take is unflinching for that tenacity, it can help for the adc oneshoting in teamfight, but every rune here is good. Revitalize is a good combo with bloodline and last stand for the heals and overgrowth is good because you are going to farm a lot and it will give you a lot of hp. I take precision as my second runes for that bloodline. You get like 25% lifesteal at mid-game. Last stand combos really good with your ult and ganks.

The itemization on Nasus is usually the same. Sheen evolition (Usually Trinity or Iceborn) and full tank. You can eve do a Stormrazor for more Q damage (oneshots). Or a titanic hydra for more damage and tanking. Obviously, you need cd for your Q, since your ult halves the cd and that means more spamming for teamfight. The normal item you do for cooldown is Frozen Heart, because it gives you 20% cd (just enough for that 40% with Trinity), it gives you mana (really need this), that 90 armor and that passive which really helps a lot when fighting in toplane or ganks. Spirit Visage is the best item with Nasus because of that healing passive and cd. That is why I recomend buying it before Frozen Heart, because it helps a lot whe trading with all that lifesteal.

You will have to max Q every time, excepting some cases, explained in the counter section above. Then you can choose. If you maxed E, max your Q then. If you max Q, you can choose between W and E, depending on the matchup. If you fight a champ with mobility or a champ that is based on autoatacks, you should max W. If you fight something like Swain or Kennen, max your E.

You should allways run with Flash and Teleport. Flash because Nasus has no mobility and Teleport for that movement between lanes in mid game and getting faster to lane to loose the less farm possible.

Pros:

You are Nasus. Your mid game is decent even if you fed in early or if you didnt stack your Q well.
Once you have 200 charges min and sheen, you destroy towers (and enemies) as if they were plushies.
You dont need kills for doing damage. You just need to stack up your Q

Cons:

If you feed early in the game, you wont suffer, your teammates will.
You need at least 200 charges to 2v1 people.
You have no mobility. Ganking you is ezpz.

You should split push once you get in the midgame. If they let you constantly farm, you will do a lot of damage and might even get a tower or two. You should move once you get like 350 stacks (that is really good damage) and start being the frontline of your team. Try to get to the enemy ADC without dying. If you see you will die if you get in, help your team taking down the tank/s.

Dont try to farm everytime with your Q. You can lose a lot of gold by doing that. You can start doing that once you get the Trinity cd, because you will have like 3-4 secs on your Q and might even oneshot mage minions.you dont need an excesive cs number. You just need your stacks.

That should be it boys. Hope you liked it ;).