Aatrox was really good before, but He got some nerfs, so don't expect much of him now, if you played him like 2 years ago.
Now you should play him like a tank.
The passive isn't that good if you are full AD.
Maybe you are asking, why should I build him tanky?
It's because of his passive, you need to stack, so 5 spells, and you have more AS and the revive. That's why, because if you would build him AD, and had no HP and armor, you couldn't have time to stack your passive and you would die.

Runes? Pretty normal. You can put AS ord damage, armor or scaling HP, MR, and again, AS or DMG.
That's pretty much it.

Yeah, I still prefer Fervor, but Thunderlord? It could be pretty fun you can stack your W to the third attack, so you have higher damage on the next AA, Q,E and then Thunderlord with the AA, that's pretty good burst, try it.

As I said before, build tanky, Blade of the ruined king is good first item, Spirit Visage is good aswell, because of the passive, more lifesteal. And GA is good allways for Aatrox, pretty much unkillable in TF(teamfights).

I prefer E maxing first. You need some poke in early, Q is good, but it'S pretty hard to hit, so I max it last.

TP is allways good on TOP, but if you think you can do better with ignite, go on!
Of course flash.

He is not really good in ranked games, if you are against someone with hard CC, He can stop your lifestealing, so yeah.

He is awesome in jungling, He is lifestealing soo much, but ganks are pretty much bad, you need to hit Q, E doesn't slow much so, Jungling awsome, ganks bad.