Hello. I'm wondering what spec is Oixte raiding with?

[Luckýstrike]

I am a huge fan of Oixte and I wished he was the one recording ur videos :P. I just returned to WoW and I am really out of date. Just powerlvled to 90 and did 4/6 the same day, but I feel like my dps is rly low compared to warriors potential. I can see that Oixte got both fury and arms spec, and I'm just wondering which one is best for raiding, and any other tips on how I can improve my dps? stance swapping etc..