A Queen

There was something or someone which caused Izekiel's memories to be shrouded in fog. He remembered a certain princess from Iyanora but nothing more. 

However, as time went by, his forgotten memories came back to him in broken pieces. Jeremiah mentioned that the emperor had a peculiar hobby, it was to indulge deep in his psyche.

He was always curious to know more about himself and perhaps it was an instinct or something else, but he believed he would find most of the answers inside of him.

And to an extent, he did.

Though he still couldn't remember all his time spent with Nesrin, he remembered that there was something gravely wrong with The Healer's Valley.

The seemingly normal people wore deceiving masks, they carried same darkness as Izekiel but they were much worse. Jeremiah mentioned how countless newborn would disappear from the valley never to be seen again.