Hey, this is my second build on mobafire and it will be for Nunu.

I will try to explain thoroughly but not too complicated.

In this build i focus on having high combat durability and Dealing tons of damage, just like phreak.

Please take time to read n' rate this, I like any kind of feedback ^^

The runes i choose are pretty basic, i take just a little bit armor to have higher durability early game, and the rest is ability power, some attack speed and magic pen.

This works great and the magic penetration is awesome both early game and late.

I take all ability power and magic bonuses in offense, including Havoc. and i take armor and magic resist for durability, and i take mana in utility because it can help u cast that one last ice blast to seal a kill

The items are mainly Health/armor and Ability power. this will make you survive teamfights and 1v1 while putting out awesome damage. Try your best to lasthit though, this build is abit expensive. You dont have to finish it to be epic though :)

Max out Ice blast first, it is your main Damaging spell, take a point in Consume at level 2 so you can eat a minion and stay in lane if you are low on health. Try to time Visionary while doing this, so you do not waste unnecessary mana.

And place a point in bloodboil at 3 just to have all spells, its nice to buff yourself if you are 1v1 or a teammate if its more than you. You will both get the buff.

Ultimate (Absolute zero) at level 6,11 and 16 ofc. this spell deals Insane damage with the magic pen runes. when casting, be wary of people with stuns or interrupts. let them do these spells before flashing into the middle of a teamfight and BOOM. best feeling there is.

thats a nice way to start getting a pentakill, after ulti slow the surviving stragglers with ice blast, buff yourself and go kill em' ;)

Flash and ignite.

Ignite is good for picking off runners, extra damage overall. etc.

Flash, awesome spell. I mainly use it to get in position for my ulti.

Say you are in a bush, 2-3 enemies close in. (best if they are mages or carry >:D), flash into the middle of the unaware enemies, channel ultimate. if they are low enough, ignite one and go after the second with ice blast and bloodboil.

I only jungle with this build in ranked, i go on a lane in normal games. The items may variate a little bit depending on how you want to play in ranked.

But take Consume as first spell when you are jungling, and max it as fast as you can. leave bloodboil at 1 point until you have to place more in it. Combine smite with consume for fast monster kills.

As you can read above i mainly jungle when i play nunu in ranked, if you dont want to jungle in ranked for some reason. Pair up with a strong carry and push mildly, Consume up hp and remember to Bloodboil your partner and not only yourself.

Okay that should be all you need to know for this build. Have fun

Note that the below games are not the best games i had, pretty mediocre short games. and 1 game where i was ks'ed about 30 times x)
but it will give you an idea about how it works