Akali is a fun burst champion whose main role is to kill the opposing teams carry. This is a build that I find particularly viable.

Other guides have a 'divided' mastery set but I solely go 9/21/0 on akali for having the defense needed for early game and the hectic situations faced later on in the game. I personally like durability, thus I use defense mastery.

***My rune set and mastery offer no bonus AD. However, those who are like me would like to have both passive active at level 1. This is now possible with Release Notes v1.0.0.113 stating:

Akali
* Adjusted Twin Disciplines to trigger at 9.5 AD and 19.5 AP to account for rounding
* Doran's Blade
o Damage increased to 10 from 9

Now we able to start with a doran's blade that gives us the spell vamp passive, are runes and mastery with give 25 AP while keeping the 8.5 Magic Pen

I personally prefer dodge seals as it has synergy with our mastery tree.

Early Game is about farming, however when you ballsy apply a mark on your enemy and do the double mark burst. This particular build/runes/mastery is meant to have the safest and efficient early game while being able to take a little more punishment later in the game when you're trying to rip the carry's *** a new hole.