Hey, this is Matthew Choi, and this is my insane LeBlanc build. By following this build you will obtain survivability and be able to deal tons of damage. First we will be starting with a couple of tips with LeBlanc.

1.ALWAYS take mid! The reason for this is because once you get your ulti you can start ganking.

2.Try your best to save mana until you obtain your ultimate. The main reason for this is because your Sigil of Silence doesn't do too much damage until you get your ultimate.

3.Remember to buy wards, they can be extremely useful for preventing ganks.

The main reason that I chose these runes is because LeBlanc relies on Ability Power, so you want to get the maximum AP at Endgame. The magic pen also really helps alot.

We choose these masteries for the extra magic pen in offensive, along with the standard 21 points in utility for extra mana regen and maximum Cooldown reduction.

I get a Rod Of Ages for the extra survivability along with more AP and mana.
I get sorcerer shoes for the extra magic pen.
Void staff for even more magic pen.
After that I get 3 kages picks for the extra ability power along with extra 15gold/per5.
Next I sell one of my kages picks for a Rabadon's Deathcap.
Next I get my Archangel staff for the extra mana, along with a 2% of my mana turned into ability power.

W>Q>R>E>Q
& they should be dead. If not rinse and repeat.

I get flash and ignite because after my burst they may still be alive, and without any skills she can't do much. While I use all my skills they may still be chasing me, so I must use my Flash summoner spell to escape.

YOU BETTER NOT SUCK WITH THIS MONSTER BUILD.