Barbed Cloak of Vapor
To get the Steam exclusive in-game cloak, “Spiked Cloak of Vapors”. (It is named “Barbed Cloak of Vapor” ingame). You need to download Age of Conan client from steam and register your new account through the client.
Download Age of Conan Client from Steam
Run the Steam client and register new account by the register button at login screen
Click the button to sign in Steam and link your account with steam
And it is done. ( It may takes a while for the cape to be showed in your claim window)