Ability Analysis

Dark Flight

Cooldown decreases by 1 per rank

Physical damage goes up by 45 each rank + 60% bonus AD

Health cost is fixed at 10% of current health (which goes into your Blood Well)

Blood Thirst / Blood Price

Cooldown is miniscule at 0.5s and it doesn't decrease per rank

Blood Thirst

Healing on 3rd Auto goes up by 5 + 25% of Bonus AD each rank (Healing is tripled if Aatrox is below 50% health)

Blood Price

Health cost goes up by 8.75 + 25% Bonus AD per rank (which goes into your blood well)

Bonus physical damage goes up by 35 + 100% bonus AD each rank

Blades of Torment

Cooldown decreases by 1 per rank

Magic damage goes up by 35 each rank + 60% AP + 60% bonus AD

Strength of slow is a constant 40%

Duration of slow increases by 0.25s per rank

Massacre

Cooldown decreases by 15 each rank

Magic Damage increases by 100 each rank + 100% AP

Attack Speed Increases by 10% each rank

Analysis

In the rough scheme of things your most consistent (non-skill shot based) form of damage is going to be your autoattacks.

If you are going to be ganking a lot then increasing the duration of your slow and reducing the cooldown on your knock-up would suggest that you would get the most bang for your buck by leveling Dark Flight and Blades of Torment. Slight prefernce for Blades of Torment first because it makes it easier to hit your knock-up.

If you are going to take an early Dragon then getting two points in Blood Thirst / Blood Price is a good approach, however after a number of Aatrox games under my belt, I would only recommend going for an early dragon if there is no obvious place to gank.

Reasons:

The first dragon only gives you Dragon's Might which increases your team's attack damage and ability power by 6%. Certainly nothing to sneeze at, but it really only starts to come into play when each of your champions has an item or two.

Riot changed it so that the enemy team gets an announcement and a the timer when you take the dragon, so the advantage of sneaking the dragon to retain sole possession of the timer is gone.

From what I've found, so far, is that if you prioritize the first dragon, the enemy team or at least their jungler will prioritize getting the second dragon.

Also as Aatrox you are going to be running Devourer and once you get it it takes 30 stacks to have it evolve into Sated Devourer. The Dragon is worth 5 stacks. So, if you take Dragon before you purchase Devourer you will in effect have left 5 Devourer stacks on the table.

Another point is that it takes Aatrox a long time to kill Dragon by himself. That is time you could be farming, ganking, counterganking, or counterjungling.

And finally, while he doesn't bring a heap of damage early game, with a slow and knock-up, Aatrox is actually pretty good at ganking by the time he hits level three and gets a rank in all three of his basic abilities.

To Do

Given foxdrop's tip of starting Q Dark Flight to prime your Blood Well to gain attack speed I need to to try jungle clearing with:

Attack Speed Marks and Quints
Attacks Speed Marks and Attack Damage Quints
Attack Damage Marks and Attack Damage Quints

To see what allows me to clear the jungle the fastest at the highest health.

What is the time to clear the Red side of the jungle, hit level three, and be ready to gank, or attempt an early Dragon?

If I decide on an early Dragon, which combination of Runes and Masteries allow me to do it as quickly as possible?

Given that Aatrox has pretty substantial AD ratios and pretty good ganks, might it be better to go

Stalker's Blade with Enchantment: Warrior
Blade of the Ruined King
Black Cleaver
Spirit Visage
Randuin's Omen
Ninja Tabi or Mercury's Treads

Enchantment: Warrior + The Black Cleaver + Spirit Visage would give you 40% CDR. I think you could also make a case for Skirmisher's Sabre though it is a while before your get Bilgewater Cutlass or Blade of the Ruined King so your early ganks may suffer a bit.

The things is, Aatrox gets a substantial amount of attack speed from his kit and ultimate. Does he actually need an attack speed item given that he is melee which means that he is likely only going to be able to get off 3-5 autoattacks on a target at any one time? Which would leave open Bloodthirster and Tiamat / Ravenous Hydra as alternatives to Blade of the Ruined King.

However, given how potent Enchantment: Devourer is currently and the fact that Aatrox gets to proc his bonus damage or bonus heal more frequently when it is fully stacked, it may still end up being better than the build path listed above.

To Do Update:

If you start with Dark Flight and prime it at 1:40 and then use it again when it comes of of cool down on the Krugs, it takes about 6 minutes to clear the entire jungle including Dragon and both scuttle crabs.

I clocked in a 6 min with Atk Spd Marks, Arm Seals, sMR Glyphs, Atk Dmg Quints and I forgot to use Smite on the big Krug to begin.

I clocked in at 6:05 with Atk Spd Marks, Arm Seals, sMR Glyphs, Atk Spd Quints.

I clocked in at 6:05 with Atk Dmg Marks, Arm Seals, sMR Glyphs, Atk Dmg Quints.

I think the 5 seconds is within the margin of error because in the first test I got the scuttle crab outside of the dragon pit on a good path back toward my jungle.

Oh I had Smite back up by the time I got to Blue Buff so I could have cleared a bit faster if I had used it, but I did not in any of the above cases.

Feel - Running Atk Dmg Marks and Quints felt a little iffy. More attack speed means that your proc Blood Thirst quicker and more often.

Of the three options, Atk Spd Marks and Atk Dmg Quints seemed to work the smoothest as far as maintaining a healthy amount of sustain vs damage output.