Nasus

Pros:
- Very viable (can run tank, DPS, even support)
- Ultimate boosts health which makes him a good diver
- Souleater passive allows Nasus to heal off of minions
- Siphoning Strike can stack very quickly
- Great turret poker

Cons:
- Mana can drop fast early

I have changed some aspects of this build, most notably the masteries as they have changed. I have removed Manamune from the build and added Shurelya's Reverie. Also, I have changed the runes to include more health per level and cooldown reduction. This is a fairly tanky build but does have damage, plus if you farm his Siphoning Strike well, you'll have all the damage you'll need.

I have changed his Summoner Spells to Exhaust and Teleport as when playing Nasus, you will usually be solo in the top lane and Teleport can keep you there. It is also good for getting anywhere in general when needed. I have taken Exhaust as well for the offensive and defensive viability of it.

For the new masteries I have gone 8/21/1. The majority is in defense due to my play style and the fact that solo on top needs to survive, not get kills. Kills are nice, but just focus on farming and stopping your lane counterpart(s). The eight I have in offense is mostly for his Siphoning Strike and auto attacks, and the one point in utility is for the Teleport buff.

Nasus' Skill Sequence is fairly balanced like the majority of the build. Build skills with balance: take Siphoning Strike, then Wither, then Spirit Fire, and aquire Fury of the Sands whenever possible.

- Soul Eater: This is Nasus' passive ability. It allows him a 10% lifesteal on attack. This can be used to heal yourself without popping your Heal spell or using a Health Potion. I have noticed that a lot of people either forget or just don't know that this is his passive and let me attack minions. But you may not always be given the chance, so a Health Potion is always helpful.
- Siphoning Strike: Be sure to last hit minions with this skill, as every time Nasus gains a kill with this skill, it will permenantly boost its strength. Late game, it has the potential to do massive damage.
- Wither: Wither is good for slowing down enemy Champions who are trying to escape, or can be used to escape from the enemy as it also slows their attack speed.
- Spirit Fire: This is a good skill for harassing the enemy team as well as farm minions. Boost Ability Power and it can drain the health from even enemy Champions fairly quickly.
- Fury of the Sands: This is Nasus' ultimate skill. He gains bonus health and AoE damage in this form. I have used it from time to time to safe my own aft end as the boost to health has given me enough time to escape to safety.

For the new runes, I focus on health more than anything. I have taken nine Greater Marks of Desolation for the armor penetration for his Siphoning Strike, nine Greater Seals of Vitality for health per level, nine Greater Glyphs of Celerity for cooldown reduction, and three Greater Quintessences of Vitality for more health per level.

I have switched up the build order a little and removed Manamune and added Shurelya's Reverie. First, buy a Regrowth Pendant and build it into a Philosopher's Stone. (Save this until the end.) Buy normal boots and build them into Mercury Treads. Then buy a Giant's Belt and build a Warmog's Armor. Next, slowly build a Trinity Force buy buying a Sheen, Phage, and Zeal. Next, build a Bilgewater Cutlass and a Hextech Revolver to build a Hextech Gunblade. Then, build a Thornmail (if they have more AP than AD, you can replace this with a Force of Nature). Finally, build your Philosopher's Stone into a Shurelya's Reverie.