When the Eldrazi were sealed away, Emrakul was remembered as a beautiful angelic figure called Em or Emeria. Em is the deity of the realms of the sky, wind, and clouds on Zendikar. She is in the middle of the three statues, and was called Kamsa by the Kor.
According to a merfolk legend, Em reigned from a place know as Emeria, the Sky Palace. After a great disaster, Emeria was torn free fom the ground, and now floats above the continent of Tazeem, tempting reckless adventurers to uncover its secrets.
Emeria’s servants, angels in their own right, were depicted as having halos that blocked their eyes, preventing them from seeing the true nature of their master.
Emrakul’s true brood are recognizeable by their seemingly pointless tentacles, and by the lattice-like patterns on their bodies. They are notable for being the only Eldrazi that are consistently symmetrical.
When they awakened, Emrakul’s brood demonstrated a sort of affinity with the Hedrons that had previously been their prison.
The broods came first, followed by the catastrophic emergence of the titans themselves.
Initially, Emrakul ravaged Zendikar like a vast, eldritch storm cloud.
After a few devastating encounters, it was determined that Emrakul has a strange affinity for organic material, perhaps the inspiration for the myths of an angelic healer. Unfortunately, it has no pity for mortals.
Somewhere in whatever is analagous to its mind, Emrakul recognizes the conciousness of Zendikar’s brave soldiers. Where it mindlessly shreds trees and wildlife, Emrakul is capable of identifying and enslaving concious minds.
Perhaps even more ominous than seeming unstoppable destruction, Emrakul has vanished. No mortal defeated it, nor even any significant number of its brood. It just left. No one knows where it has gone or what it plans. Only that it left a vestigial brood behind, either by accident, or as part of some twisted scheme.
The only person who may know something is Nissa Revane, who was visited by a cosmic revelation about Emrakul. The details are vague. Either she was contacted by Emrakul itself, or the plane of Zendikar used some of the last of its power to share something important with her.