Are you tired of being harrassed and poked by ranged champions?
Do you always struggle because of lane bullies?
Introducing my new Nasus build... because AP is OP.

QUINTESSENCES

-3x GREATER UINTESSENCE OF LIFE STEAL (+1.5%) : they will help you staying in lane

MARKS

-9x GREATER MARK OF ATTACK DAMAGE (+0.95) : they will help you last hitting

SEALS

-9x GREATER SEAL OF ARMOR (+1) : they will make you harder to kill

GLYPHS

-6x GREATER GLYPH OF COOLDOWN REDUCTION (-0.83) : they will help you stacking faster
-3x GREATER GLYPH OF MAGIC RESIST (+1.34) : they will make you stronger against AP champions

OFFENSE TREE

- Sorcery will give you more cooldown reduction for stacking
- Mental Force and Arcane Mastery will give you more ap and more damage in general
- Butcher will just help you last hitting

UTILITY TREE

- Fleet of Foot will help you chasing down opponents or escaping from bad situations
- Meditation will increase your mana regen to stack faster and cast more spells
- Summoner's Insight will reduce the cooldown of your summoner spells which allows you to use more teleports and more flashes
- Alchemist , Culinary Master and Vampirism will help you going through the lane phase
- Greed and Wealth will give you more initial gold and over time income
- Intelligence will give you more cooldown reduction
- Wanderer will allow you to go back in lane faster and to roam better

- Doran's Blade will give you extra HP, AD and lifesteal to go through the lane phase
- Sorcerer's Shoes will give you extra magic penetration which allows you to deal more magic damage
- Athene's Unholy Grail will grant you an insane amount of Cooldown Reduction, a lot of Mana Regeneration, a little bit of AP and some Magic Resistance
- Lich Bane will give you a lot of AP, Mana and Movement Speed which is always good on Nasus because you can be kited very easily. It also has a passive called SPELLBLADE : after using a spell your next basic attack will deal bonus magic damage based on your AP which is awesome for your Q since it is considered as a basic attack
- Rod of Ages and Rylai's Crystal Scepter will both give you a lot of HP as well as AP; The Rylai's will also apply a slow whenever you damage an enemy with a spell
-You can also consider to build Zhonya's Hourglass because it grants a lot of armor ability power and since you're not going to be very tanky, its active ability may be very usefull

I know that is very common with Nasus AP to level up E first to maximize your damage output as fast as you can, but i really like to skill the Q first because you can stack very easily with the lifesteal/spellvamp given by the runes/masteries, and if you manage to do it you will deal a lot of AD and AP damage, which will allow you to DELETE squishy targets and it will make difficult for the enemy tanks to be effective and strong against you.

+21% Lifesteal at level 1
+15% Cooldown Reduction at level 1
+Cooldown of Summoner Spells Reduced by 10% (more stacks with teleport)
+More sustain with Biscuits
+You can spam your spells after purchasing the Athene's unholy grail
+Insane Ultimate Damage (fast DRAGON and BARON)
-You won't be very tanky
-Your E won't do a lot of damage until mid game

This is the end of my Nasus AP Build, i hope you guys enjoyed it, if i missed to tell something or you didn't undestand some points feel free to leave a comment and don't forget to look at my other Top Lane builds. :D