It's back for the very final time. So make the most of it :
Beginning Tuesday, September 2 at 10:00 a.m. PDT, through Tuesday, September 16 at 9:00 a.m. PDT, we’ll be applying the Gaze of the Black Prince buff for the final time before the Warlords of Draenor expansion. This buff will increase the reputation gained with the Black Prince by 100%. It will also increase the chance of obtaining items from his foes needed as a part of the Legendary Cloak quest line including: the Secrets of the Empire, Sigil of Wisdom, Sigil of Power, or Titan Runestone.