Well, Basicly in 4.0.6 Crusader Aura + Aura Mastery was going to get nerfed because it was to overpowered in rated BGs...Well heres the thing! The nerf never went through on live realms!!
Enjoy before it get hotfixed
Quote from patchnotes
- mGsHoly
* Aura Mastery: This ability no longer increases the benefit granted by Crusader Aura.