This build probably looks strange the first few times you see it, but I have had success with this build in shutting down opposing top lanes, pestering enemy junglers, and carrying my team through the late game when other lanes haven't done so well. It takes Akali away from the conventional glass cannon type champion, and makes her very strong early game as well as late game.

Why so much attack speed and health? Akali is really fast, and this makes her really, really fast; the combination of going into lane with that kind of attack speed, and just short of 700hp, and the glyphs giving her a decent amount of early game burst makes her able to be considerably dominant in lane from level 1. That being said, everyone knows that Akali is typically very weak until level 6; this gives her the ability to get farmed up until then, and be strong before level 6, and rather terrifying once she hits 6.

'Rush the Ravenous Hydra?! what..' A reaction I get from most people that notice my build. Yes, I rush the Ravenous. Having the glyphs of AP and getting an amplifying tome before rushing the Hydra, you will have enough AP burst to kill people; getting the Ravenous Hydra will give you somewhere around 30% spell vamp with Akali's passive, and will make you able to farm your lane, and quickly steal buffs from the enemy jungler to throw off their game.
Sheen, Zephyr, Trinity Force; this IS a hybrid build, and notice that this build doesn't at any point contain boots. Any time I can do the Zephyr/Trinity (or Zephyr/Shiv, Zephyr/Phantom Dancer, or something similar) as opposed to getting boots, it opens an item slot that isn't being filled with an item that isn't helping you do damage.
Liandrys, Hextech, and Rylais are all items that no one typically questions on Akali, though people may question why those instead of a Rabadons, Zhonyas, Deathfires, or just something with more damage. These make you tankier, that's why. This item build is all about sustain; doing a lot of damage, and staying alive to do more damage. Sure, you don't quite have the insane burst of a glass cannon Akali, but you can carry so much harder this way.

Akali is made to charge in and kamikaze; with the extra tankiness and passive spell vamp (which is even more tankiness), she is now able to charge in and just kill stuff, as opposed to dying during the late game. This makes her really annoying to deal with for enemy teams, but your team will love you, because now their 'tank' is charging in for them, taking damage, but also is dealing a ton of damage, because it's Akali. Your team's tank is Akali. huh. It takes that a bit to sink in once you've seen it work.

No other Akali is a threat to you. Anytime I've done this build, or any similar build on Akali (or Diana, Fizz, or other champions that aren't technically hybrid, but really are ;P) I have never been threatened by another Akali, even if they have been fed.

Don't trust this? Roll top lane with it and just see for yourself ;)