Hello, This is Alcaeus here with my very first guide. First off, I bet I know what your thinking.
Oh, he's a silvy, he has no idea what he's doing. Truth is, your wrong. I'm a good player aiming for gold this season. My main is jungle, but i do not mind doing any other role, especially top.
I like playing tanks, or fighters. Most of my guides will be simple, easy to read, and mostly consist of only words. I have played Aatrox jungle ever since he was released, and i can guarantee you I am definitely not the best Aatrox, but i am much, much better than most Aatroxes you see in my division. My Lolking profile is located at this address- http://www.lolking.net/summoner/na/30127199

It's very simple, counter pick the other team. Also choose Aatrox if your team needs a reliable Tank that can initiate. Aatrox does especially well with any lockup champs. (For instance, a good team would be- Pantheon top, Aatrox jungle, Yasuo mid, Jinx marksman, and Leona support.)

PROS
Good sustain and tankiness
Great initiation
Looks epic
Good ganks
Deals tons of damage (Phreak approved)

CONS
For new players it's hard to find his potential
Gets set behind if not farmed properly in the jungle
Dance sucks (I know, I'm a hater.)
Easily killed if he does not get backup

Your W is a great farming and sustain tool in the jungle. Max this first to maximize your damage and clear time. Next, get your Q. It will help with any level 2 ganks, and it provides a decent amount of damage. Take E next, it makes your ganks even stronger. Max this second for greater chases and a slow for the enemy marksman. Max Q third, it is usually used for initiating fights or ganking, and not so important in the jungle. Also, always make sure your team knows you are going to jump on someone.

Flash provides for a great escape, which can be used for a faster, more reliable blink than your Q. Smite should be taken on all junglers, and if you don't take it, your making a very bad decision.

These items provide a great balance. Even though it's a pretty big amount of money required to get this build, games usually don't last this long, and if you play right, you should be able afford this with no problemo.

It's the jungle, how hard is it to farm? Anyways, always use your Hydra's passive, and always switch your w to be efficient. Make your Darkin Sword purple if your above half health, red if your below half health. And don't get too caught up on farming, there's some lanes in need of a good gank every once and a while.

Always communicate as efficiently as possible, and don't make any stupid mistakes. Make sure your team always knows when you are located, and vice-versa. Make sure your team is all together when you team fight, and try ulting as soon as possible. Really, you will be the self-center of the team, so always do things for the better of your team, and not just yourself.

This concludes my short guide on Aatrox, the Darkin Blade. I have much experience in the jungle, and i'm very happy to help anyone that would like to improve any skills. If you would like to play a couple games and better yourself with this demon, friend request me (NA username- Alcaeus) and i will try to get back to you as soon as possible. Thank you for reading my guide, and i would be very happy if you spread this with your friends who are interested in Aatrox, or want to be better with him.