Magic: the Gathering
Ulamog, the Ceaseless Hungerand
Kozilek, the great Distortionand, through the use of the leylines and of the Zendikar's Roil, the manifestation of these titans on Zendikar were destroyed.
Nahiri, the Harbingerwas planning her revenge against Sorin, which abandoned her when she needed the most. Nahiri, Sorin and Ugin imprisoned the Eldrazi in Zendikar millennia before, but when they got freed, none of her friends came to her aid. The Lithomancer went to Innistrad to question Sorin about this and ended up caged in the
Helvaultfor a thousand years. Liliana eventually destroyed the vault and Nahiri became free, but Zendikar was already almost completely consumed by the Eldrazi. To take revenge on Sorin, she attracted
Emrakul, the Promised Endto the vampire's birthplace, the plane Innistrad. The presence of Emrakul brought madness to the plane, transforming every living thing in servants of the Eldrazi.
"This is all wrong. I am incomplete, unfulfilled, inchoate. There should be blossoms, not barren resentment. The soil was not receptive. It is not my time. Not yet."
Bloodhill Bastion, but the Eldrazi exist since before the origin of time itself, so they existed before the beginning of everything. Probably the origin of the Multiverse came through an event like the "Big Bang", which gave origin to the Blind Eternities and then the planes of existence. The Eldrazi might be a manifestation of the Blind Eternities and Emrakul may be the origin of life, the first creature to inhabit the world may have come from her. The titans work in a cycle, based on what we know: They go to a condemned world; Ulamog consumes it; Kozilek reshapes it; and Emrakul creates new life. If the cycle began with Emrakul, life came from her. She affirmed herself that she is the origin of life and, during the Battle of Innistrad; She knew that she shouldn't be there, as it wasn't yet the time to recreate that world. She understood that and realized the other titans weren't there. Something was wrong and until the moment that world was destroyed or renewed, she would remain trapped on the moon. However, this day might never come, so it is possible that we will never see Emrakul again, maybe just her influence coming from the moon. But, if there isn't a broken world, she won't be able to act.