Post by Shadowheart10
The Heart is all that remains of the Old God Y'Shaarj. It's actually much larger than it appeared in the trailer; play the scenario mentioned above and see its real box for yourself. Before the trailer, it was actually a dormant bauble sealed under the earth (possibly by Norgannon, due to the
suspicious amount of discs associated with Mogu'shan architecture and its underground Titan secrets; it'd make sense that he'd have hand in the Heart's sealing. The arcane chains are convincing, also.) and watched over by
Norushen, at least up until the goblins dug too deep and
this idiot ran up and bothered it, with
interesting results.
With Crafty's death, it's safe to assume that what little "echo" of Y'shaarj's consciousness that made its way out of dormancy went back in, and stayed back in, until Garrosh brought it up and had the genius idea of giving Y'Shaarj a little wake-up slap by dumping his heart in the magical life-giving Pools of Power at Mogu'shan. Unfortunately, it works out exactly how Garrosh wanted it to, and Y'Shaarj comes back to life, though disembodied with his consciousness trapped within his heart. In the raid, this will end up working out for both Warchief and Old God, since what Garrosh wants is
to control the full power of the Old God, and what Y'Shaarj wants is
an avatar through which he can wreak destruction on Azeroth, as he's demonstrated with Crafty.
Ultimately, Big Y gets his ghastly ass kicked for good.