This is my simple destruction build to Akali, more of a private guide, not meant to be public. But criticism is accepted!

This guide is covering items, mastery, why to choose some items and why not to choose others.

I go heavy on the Offensive tree because I find it helps me more often than not. A lot of Akali players pick up more in the Utility and Defensive trees, but I like this way better. The crit and attack speed comes in handy. I feel Akali can juke enemies with Twilight Shroud to easily to need a lot of defense and the utility tree just really doesn't fit Akali as well.

Start out with the Boots of Speed and Health Potions, this is for early game survivability and the ability to lane longer to work towards your Hextech Revolver. Build your shoes in to the Sorcerer's Shoes and then begin your way to the Crystal Scepter. After this begin your way to the Lich Bane, I love this item oh so much. Start with the Sheen first, it provides a ton of extra firepower. After this grab your rod and build the Deathcap, this item will boost your AP out the ***. Build your revolver into the gunblade.

Now here is where things become dependent on you. If you want survivability you have a number of options. You could go with the Banshee's Veil or the Guardian Angel. I go with the Void Staff for that extra AP and penetration. It's entirely up to you. You could also substitute in a rageblade.