How do you become a doomknight on AQ

Step 1: Go to Shadowfall by either clicking it on the map or by typing "/join Shadowfall". Step 2: You will see a guy in the left that has black armor . Step 3: Click his icon on the top that looks like "!" and look for the Doomknight class. Or if you want to look good, Buy those different armors. (P.S. I'm not sure if they are bought through AC's or Gold.)