Nasus was the second champion that I bought, after a long time of playing him as my main tank, I have decided to create a guide for him. While some people insist on building Nasus as a DPS champion, I find he is more of an asset to the team as an off-tank. His main source of damage output comes from Sheen + Siphoning Strike. I level up first, as it is important to farm last hits with it as much as possible. Next I get wither, I find it to be helpful if you need to protect an ally's escape or help chase down an enemy. Spirit fire is good for weakening other tanks, it lowers armor, however it is easily avoided. Spirit Fires should not be used to farm, they are extremely costly with your mana, and you will find yourself b'ing for mana constantly if you insist on spamming Spirit Fires. Even with runes and chalice/tear, spamming Spirit Fires is not the way to go. Something that was recently changed about Nasus is that his Q resets his autoattack. What this means, is that if you press Q after autoattacking, Nasus will instantly autoattack again, with Siphoning Strike being used. Essentially with this, you can 'double hit', which aids in timing last hits, as well as hitting turrets or champions more efficiently.
Additional note: I had a random surge of downvotes that dropped my rating down by like 7%, I would very much appreciate your help in raising my rating back to what it previously was. :)
Ability Level Sequence / Game Play
Early Game (lvl 1-6)
Grab Q as your first ability and regrowth pendant + hp pot. It's good to lane with a dps or caster, preferably ranged; you can also solo top, but know that Nasus does very poorly against ranged in a solo lane. Nasus can (and should) lane very passively. Against certain comps,he can be more aggressive, and certain other comps will be able to deny and starve him of his last hitting. Make sure you get as many last hits with Q as you can, I cannot stress that enough. With the recent buff to his Q, last hitting to farm Q is extremely rewarding. There is a certain point in the laning phase where Nasus can become dominant. Once you've got merc treads and chalice, your Q should be around lvl 3 so its CD should be relatively short. You can afford to be more aggressive. Remember to utilize your passive to stay in the lane. Nasus takes harassment to the chest. You should not have to b for hp very often, if at all. Also remember to wither enemies that get turret aggro.
Mid Game (lvl 7-13)
You should be getting your Glacial Shroud then working toward whatever item will benefit you next. Q should be around +100-150, if not then it's time to start working harder on those last hits. If you want to gank a lane, run out of the bush with Ghost, Wither the enemy and Exhaust him if you need to. You should be able to tank turrets to an extent, so you and your allies can get the kill. Ult if needed. In skirmishes, stay in front and remember to double hit your target (autoattack immediately followed by Q). Wither the target or use Wither to help a team mate get away. If you ult, you should be committed to the fight, so as not to waste it. Assuming Q is farmed well enough, you should be able to 1v1 squishies, your life steal passive mixed with a powerful Q (especially if you have Sheen) will allow you to fight well 1v1. If your ever passing through the jungle, don't hesitate to grab some last hits on the wolves or wraiths.
Late Game (lvl 14-18)
You should be on the way to completing your build. Q should be any where between + 250-500. Having Q farmed this well will essentially make you a powerful off-tank (instead of needing to buy DPS items). Although farming is still important, make sure you are with your team in case a fight breaks out. You can hit turrets hard with your double hit. Try to throw in a double hit every time your minion wave reaches the enemy turret. Although you are an off-tank, your main role is tanking. A good way to scare off an enemy squishy is to Wither them and then double hit them. You can choose to chase them, but make sure your team doesnt require you to be tanking during that time. Throw Spirit Fires down, by lvl 5 Spirit Fire has good armor reduction, which will help your team dominate squishies and even deal good damage to their tanks. Remember, Q does have the potential to crit, so the Trinity Force can help in that sense too. With Q heavily farmed and having a TF, I've dealt as much as half a squishy's HP in one hit, around 1300 damage.
Ghost: Ghost is good for escaping/chasing enemies. Also it goes well with his ult, enabling you to move around the fight quickly. Nasus is very easily kited so Ghost is an important spell to get.
Exhaust: Exhaust followed by or preceding Wither makes for a very lengthy slow. Also the blind-ish part helps against champs like Tryn and Yi
Teleport: Teleport helps you get around the map quickly. If you see an opportunity to farm Siphoning Strike if a large group of minions has formed, you can go farm it and teleport back to your team if you feel that a fight is about to break out. Also helps against backdoorers
Cleanse: Cleanse gets rid of a CC that's on you (not suppression though). This helps because a CC'ed Nasus can't do anything.
Flash: Flash can be used in place of ghost. It's good for chasing/escape.
Ignite: Ignite can help you get that little bit of damage in to ensure a kill. It also can be used to counter champions like Dr. Mundo.
Clarity: Clarity is good to have if you're having serious mana issues.
Clairvoyance: This is good for checking things like dragon or baron. It also can have other uses too.
Heal: Heal helps you tank more damage.
Fortify: Fortify helps defend turrets. It's better for champions with a Taunt, but it still can work for Nasus.
Revive: Revive is kinda dumb...I guess you can use it if you're really into this spell. It can only be used when you die (something you shouldnt want to do :P) and it has a very long cool down. Just not worth getting, there are much better choices.
Rally: Rally is also , other options are much better.
Smite: Although Nasus does have the potential of jungling, I find he's better in the lane building off-tank instead of more towards DPS.
Spirit Fire vs. Siphoning Strike
Many Nasus players choose to upgrade E over Q. I believe the reason for this is so that they can farm better. At lvl5, E can kill the caster minions and almost kill the melee ones. You can kill the melee ones with Q to finish them off.
This is where my argument arises. Why farm with E to get gold, when you can farm with Q to get gold AND more damage output? The way I see it, every time you kill a minion with something other than Q, and Q is not on CD, you are sacrificing potential damage output.
Many Nasus players would argue "well I only need 1 or 2 levels in Q and I can farm it perfectly. If you don't level Q up quickly, your CD will impede your Q farming. I level it for lower CD, and so that it deals more base damage, which makes it easier to last hit with. I doubt you will be able to farm +477 Q in 31 minutes when it's only upgraded to level 1 or 2.
Spirit Fire is not a very reliant farming tool. Yes, it will hurt the minions, it is an AoE DoT, the minions will not move off of it, so they will die. However, being a DoT, there is no way to ensure that it will 'last hit' the minion(s). The Armor reduction will actually help your own minions deal more damage to the enemy minions, which makes it even easier for your last hits to be stolen by friendly minions.
When my Q is on CD and I need to make sure I get a last hit, I just auto attack. It's not that difficult, just wait until the minion is very low and then smack it. You don't need Spirit Fire to kill minions when Q is off CD, auto attacking is a more reliable way to ensure you get the money for last hitting when Q is on CD.
Lastly, Spirit Fire costs a **** load of mana compared to Q. At level 5, Spirit Fire costs 130 Mana, compared to Siphoning Strike's 40 mana cost at lvl 5. I would find it pretty difficult to manage spamming Spirit Fire only for the purpose of farming minions (enemy champions are not going to stand on it). Mp5 would be extremely important to ensure you can do this. By the time I get philo, I am comfortable with using a lot of my abilities more often, because Q doesnt cost much mana, and I don't have E very highly upgraded, so it doesn't cost too much mana at that point either.