Akali is one of my favourite champions. I am very much into Assassins, and I think that Akali is superb among the assassin group. She looks awsome, has insane burst damage, can flee easily (stealth) and is to able jungle in almost any situations. So, this build tells you my way to execute enemies with Akali. Like usual, I go for great AP -> Burst!

And now before you really begin, I warn you about my Pad Engklish.

Pros

Outlook
HUGE burst damage
Stealth
Ranged ability (R) <- Ability to go through walls (Non-ally target needed!)
Nice AoE for an assassin
Passive ability
Lots of people are going to say "GJ" to you

Cons

Squishy in a way
Picked by ranged
Vulnereable to CC
When you start using her, you may have energy problems
Lots of people are going to say "N00B" or "HaXXor" or "Feeded" to you

Greater Quintessence of Movement Speed
With these I am going for movement speed, which is critical to all assassins. Unlike Xin Zhao you are not going to buy Phantom Dancer so well take a little bonus from here.

Greater Glyph of Cooldown Reduction
Glyphs go for CDR. It's going to be your only CDR with Sorcery unless you max Mejai's (That may happen often), because Akali's cooldowns ain't so long, and if you spam them too much, you will have energy problems. It's a pity that there aren't any runes/masteries/items to increase energy regen. D:

EDIT: There are now Energy regen rune, though they aren't available on the run planner. They are quintenssences, but I'll keep these in my build. :D

Greater Seal of Armor
Flat armor runes to keep you alive further.
Thanks to reQQuiem about the idea!

Greater Mark of Magic Penetration
Granys you 9,5 magic pen from the beginning. Also a great kick in the mid-late game.

Masteries are shared 21/0/9 (A few times I've had that amount of kills, deaths and assist with this build.

So I'll explain why these masteries

Havoc This is the whole thing! 4% more damage in every way. 4%! That's awsome boost in the early game.

Cripple You have exhaust, this mastery is great for it. NOTE: Do not use if u do not use exhaust spell!

Archaic Knowledge 15% magic pen. Do I need to say more?

Awareness Helps you to level up faster. It is a great help if you are one step further that your enemy.

Utility Mastery 15% buff duration. Great for all buffs, especially Baron buff. This point is meant to be used. Grab all the buffs you can!

Ok, I prefer Flash and Exhaust for a few reasons:
A) Both can be used to attack or flee.
B) Flash is great to use inside Twilight Shroud: Enemies cannot see you to flash!
C) Exhaust can be used to save a teammate in low HP that is being chased.
D) Twilight Shroud + Exhaust = ULTRASLOW! (Can also be combined with Rylai's!)
E) Flash + Shadow Dance = very great distance traveled in a really short time. GREAT for chasing fast opponents
F) Exhaust Turns the tide when you are opposing a *********king DPS, like Yi or Jax.

These spells are also ok:
Teleport - For faster ganking, but I prefer running to this
Ghost - Speed increase, good choice, but I think u won't need it. You've got your ulti to chase enemies.
Cleanse - For hard CC opponents
Ignite - Also good with Akali's burst, but you'll kill your enemies also without this
Clairvoyance - Now you think WTF?, but there is a way to use this spell. You can use it to jump over a wall with ulti to jungle to flee or just move faster.

Off-limits!
Heal - You'll get your own heal when you get some AD
Smite - No need
Rally - ...seriously?
Clarity - She doesn't have mana...
Fortify - Leave it for tanks/supports
Revive - You aren't gonna die

Twin Disciplines Great passive, which turns Akali into a viable hybrid. With my items I get huge amount of AP which gives you AD that helps with the combo when you hit an enemy affected by your Mark of Assassin. Also, a little AD helps you to stay alive along with Hextech Gunblade(AD comes from this item!).

Mark of Assassin Is a great ability. Throw your kama to an enemy from distance, close him, perform autoattck and you have done a great amount of damage. Also, because the debuff is longer that tthe skills cooldown, you can hit your enemy with two of these at the asme time and then autoattack for HUGE damage. In early game great for owning those pesky bigger minions.

Twilight Shroud Your stealth. While you're inside it, you get Armor & Magic Res and of great way to close ranged enemies. Ranged enemy in lane = Twilight Shroud -> From inside itcourse, become steahted. Also, all the enemies in the shroud are slowed. This is a use Mark of Assassin -> Shadow Dance + Autoattck -> Retreat or fight

Crescent Slash A nice skill for last hitting minions, and works well with your burst. Its damage is affected by both AD and AP(Yeah, goes hybrid)Nothing special to say.

Shadow Dance Is a great ultimate. It does fair amount of damage, has a great distance to use, bring you to melee distance from the target which makes the other skills able to use quickly. It would be nice if you could use it to an ally to flee like Jax's Leap Strike. But, one of my favorit ultis.

Items, items, items. I usually start with an Anplifying tone and a Health Potion. This activates the other discipline and help you to stay alive a bit longer. Then I go for Mercury's Treads because of nice tenacity amount. If the enemy team hasn't much stuns, slow, etc. You should switch these with Sorcerer's Shoes. After this, take Doran's Blade to activate the other discipline early.(Thanks to reQQuiem for the idea, again) Sell it when u need money or space, but not preferably before you get Hextech Gunblatde. Then upgrade the tone along with Giant's Belt and Blasting Wand into the only item, that I would call NECESSARY to akali, Rylai's Crystal Scepter. It grants you HP, AP and SLOW. THIS IS A MUST! The next two items are Mejai's Soulstealer and Hextech Gunblade. Depending on the situations, choose the order carefully. And also, when you are beginning with Akali or you see you won't be able to get some much kills quickly, switch Mejai's to Void Staff. Then I get Rabadon's Deathcap that brings you so much AP. It though costs 3600G but it's worth it. The final item which leaves your opponents cofused with its damage, the Lich Bane. Works great with your Q combo. It just gives you an insane amount of damage to your burst.

I am closing and thank you for your time while reading this guide. I wish that you would vote and comment your all thoughts, so I can improve this guide.

Akali in a few words: An amazing assassing with a huge burst, stealth and ability to flee easily.

Good luck and hope this guide helped you to master the Fields of Justice!

Special thanks for helping the guide out:
reQQuiem

Akali is one of the greatest assassins, but she isn't very much able to directly SUPPORT other players. You just go, slow, burst and back off from your enemies. Of course, doing the damage is the main thing, after all. So here is your skill rotations:

Basic combinations:

Normal combo:
Q -> E -> R -> Autoattack -> Q -> E...
Use W anytime it's needed.

Aganist ranged:
W -> Approach -> Normal combo

High busrt combo:
W -> Q -> Wait in the shroud -> A new Q -> R -> Autoattack -> E -> Normal combo

Useful tips:

1. While in shroud, stay on the edges to avoid AoEs.
2. As detailed above, you can use double Q + autoattck for burst.
3. When ally + enemy fight, wait in the bush and attack with R to easily killsteal (lol xD)
4. Have fun

8.8.2011 - Guide created
10.8.2011 - Playstyle tips added