It's the human perfection inside a virtual game.

Search it on the internet, people make fun about it, but they don't know that the best nunu is the one that has the mind games.



So, first, you have the Spellbook, start going top-lane, and your team will be tilted at this point, but don't mute them yet! Wait for the comeback.
Stay inside the top-lane middle bush, the one next to the farming lane, then, stay there and wait inside, when the enemy top-laner come closer to farm or abuse your ally before the minnions, go there and spank him, since you have spell thieves your AP will be bigger, so your Snowball will hurt, alot! Then just keep punching the nemy until he dies, if you get stunned or some type of slow, use Cleanse and keep punching, while you hit him use Ghost as well to give more move speed while running on the enemy.

If the enemy top-laner don't died, go back to Base and buy some extra potions or Wards, then, select Teleport for your new Summoner Spell, and Teleport to bot-lane. Remember to not spend too much time at top, because at this time your adc will be more than 10 farm back, but, come to lane more agressive than before.
Spend your mana poking the enemy adc or support if he is a poke-champion and then, go back to base to buy some boots and other things at the builds.
Remember to keep roaming, you should have ganked more than the Jungler at this point.
Your level will be very low compared to the enemy team, so spend some time at lane and farming.
Prioritize defeating large monsters from the enemy jungle and taking objectives (dragon, rift herald and even baron if you have the chance). The entire game will be filled with tilt, mostly from the enemy team, because if your team knows who is the big boy they will not complain.

At the late-game, force team fights and make one of your team mates go split while your team is fighthing.
This is enough to make you win the entire game without doing nothing more than tilting the enemy team, and yours too.