Welcome to my Guide. i have 5 different and similar builds that you can look at. All of them focus on geting 1000+ ap and making nunus ult hit for at least 3655+. (-note calculations for baron ap boost or for ally will of ancients boost....baronis=56 and will of ancients= 42
so if you have these 2 buffs then you can have a max of about 1700 ap whith nunu ult =5405 per ult)

Build#1

Build 1 focus's only on getting max ap which is about 1600 total.
PROS AND CONS TO BUILD 1

PROS
-his ult hits for 5155 damage
-his ice ball hits almost for 2000 damage
-he can heal massively off minons healing for about 2000 for one minion
-if he have blue buff he can ult almost every minute and ice blast every 4 seconds
-he will cause enemies to run in terror and rage quit
-you will get many wtf how did he kill me so fast
-SQUSIHY KILLING BEAST

CONS
-he dont have boots
-he doesnt have healthy amount of hp
-he limited to only his iceball and ult
-if magic resist is built by tank his ult doesnt deal as much damage

Build#2

Ok by now you may not be sure why i reccomend such items or why no boots or why there are more than one of each item.Well ill explain how each item works to make more ap.

Build #1

build 1 is for max ap. It also gives you lots of mana and mana regen. With full build you get 1600.98 ap. It doesnt show on the screen with all the stats but it is that much.

ITEMS
969 b4 5% mastery increase then becomes 1017.45 mana

Mana From runes @ lv18= Marks=189.54 + Seals=189.54 + Glyphs=230.04 + Quints=225.18
=834 mana

Mana from Staffs Okay you only get the bonus of 1000 fromonce but each staff gives you 400 mana each and 400x5=2000 and then add bonus and you get 3000 mana.

Total mana 1017.45+834+3000=4851.75mana

Now how does this transfer into ap?1000 bonus only happens right but its 3% mana into ap stacks. So 3%x5=15% of your mana becomes ap. So 4851.75/100 x 15= 727.76 ap

Eachalso has 45 ap per staff so 45x5=225 So from the's and mana with runes you get 952.7625 ap now add aand thats plus 140 ap and add awhich is plus 40 and then you have mastery bonus 10.8 ap at lv 18 and that is 1143.5625 ap! but wait you still have the 40% bonus from the http://edge4.mobafire.com/images/item/rabadons-deathcap.gif so 1143.5625/10 x 4=457.425
now 457.425+1143.5625=1600.9875 ap! 1600 AP!!!!! now nunus ult scales 2.5 per ap so 2.5 x1600=4000 and his ult does 1125 damage without any ap so add 1125+4000= a ult with 5125 damage!!!!!!! that makes it where pretty much only tanks survive!!!!! talk about op!!! and with this build you have about 25% cd
from then potion and masteries so you can ult everytime they respawn! in addition you also regen 128.12 mana per 5 sec this is the build with max ap....it may not be the best build but this build has most damage an has you using a 1875 nuke every 4.5 secs and ulting every 76.5 secs....this build is not the best but if you want to see people go wtf then this build is for you.... Greater Mark of Knowledge

build #2
1419.5
40%cd-most ap

build#3
1103.1
40%cd-lich-rylais slow

build#4
1223.5
slow and lich

build#5
1137.944
-40%cd-lich bane burst-rylais slow and hp-hextech life steal spell vamp and ability-plenty of mana

build#6
1363.5
40%cd-lich