Not Updated For Current Season
The masteries shown here are not yet updated for the current season, the guide author needs to set up the new masteries. As such, they will be different than the masteries you see in-game.
First Guide... Don't be too mean to me!
This guide is what I use when I play as Nasus in the Twisted Treeline 3v3 game play. It goes more tanky than damagey but that doesn't mean that nasus doesn't dish it out! The biggest issue that I feel people have with Nasus is that he is a LATE game champion. He isn't going to be pwning much at all in beginning and honestly isn't really that helpful until level 6 when he gets his ult. Sounds lame and doesn't really sell him too well but his late game makes up for it 100%!
Don't wanna scroll down and read everything? I wouldn't either. This is going to be a quick sum up of the Nasus guide.
Items: Go tanky based on situation. Get a sheen ASAP!
Runes: MR/Armor/ARP/HEALTH, good for staying alive and doing some nice Q damage
Skills: Q, W, E, then max E, then Q, then W, ALWAYS getting R when available.
Laning: Last hit minions with Q to get that as high as possible. If possible harass with E. As later game comes, push with E.
Ignite- Great for fleeing enemies and great for going against champions with a good heal ex. Mundo. If others on your team have ignite you can get other spells that you are more comfortable with. I sometimes run with clarity or heal.
Flash- Nice to help jump away from enemies and leap over nearby walls. Can be substituted for ghost which is great for chasing down a fleeing foe!
9/21/0.. gives you the damage reduction and magic resistance bonus from the start, as well as giving extra hit points and health regen for longer time in the lane. The offensive tree gives a little crit but more importantly gives some cooldown reduction that will help when farming the all mighty Q and keeping that ult off cooldown.
I go complete tanking runes. Health quits, armor seal, mr/lvl glyphs, and then I get armor pen marks which is obviously for the Q. If your squad you are running with is 'beefier' champs then other good runes would be CDR glyphs and mp5/lvl seals. I wouldn't recommend changing the armor pen marks tho, it is essential for doing damage with your Q.
As a tank you know that items needed change each game. I always start with the dorans, boots, sheen, and legion. I will usually go for a sunfire cape after that but if they are AP heavy I would skip to a quick banshees to help reduce and negate that damage. And of course if they are running a yi, xin, and garen... get a thornmail asap.
Always start with Q. The sooner you start last hitting the more damage you do quicker. After getting (Q) I like to get spirit fire (E)to help keep minions off the turret and even harass the enemy champions unless they are smart in which case they wont get caught in it, but then it keeps them away from minions and by rank 4 it will wipe out the caster minions which allows for excellent pushing capabilities. The (W) is nice to help teammates catch and kill fleeing champions, but I don't feel that leveling it up before (Q) or (E) is more important. ALWAYS ALWAYS level up Nasus's ult.. (R). It is completely crucial to be able to always use that in a team fight. It drains every enemy doing huge damage and makes them weaker, it also makes you have waaay more hp's and you look freakin sweet! (especially with the Galactic Nasus skin). You need to try to pop it as soon as the team fight is engaged, but you can't blow it early and have them just run away while you are running around dumb. Fine line between the 2.
If a minion is almost dead.. use Q and kill him. The quicker you get this ability farmed up the quicker you and your team can drop turrets and kill enemies which are both fairly important aspects of the game. E can be used to bring enemies out of bushes and to do some damage here and they if they haven't learned the sand on the ground is actually hurting them. As the game goes on E will be used to push through minions very quickly because at rank 5 and will kill an entire wave. (minus tank minion, but a well placed Q will do that!)
I made this guide very quickly. I plan to come back and make it pretty and fix errors that I am sure that I have. Please leave constructive feedback so I can revise and make this better.
Thank you all for taking the time!