How should I build Aatrox?

I'm not entirely sure as to how I should build Aatrox. Should I build him as a tank, or an attacker? I currently build him as an attacker, and my build is: Berserker Grieves, Blade of the Ruined King, Blood Thirster, Randuin's Omen, Spirit Visage, and Zephyr. I understand that Aatrox isn't a very popular champion, but I love using him, so I would be glad to hear some of your suggestions and/or tips on building and using Aatrox.