Long ago, towards the North edge of the continent, in a place called Lasra, lived two twins, Shatu and Sinna. Though the brash, outgoing Shatu was quite in contrast to her quiet and reserved brother, the pair got on well, and the locals came to think of them as being like night and day. They went through various adventures of their own, and long story short, became Shatu the Radiant Dawn, goddess of the sun, day and revelations, and Sinna the Shadow of Dusk, god of the moon, night and secrets.

However, Aya, a friend of Shatu who desired her for themself, was jealous of how close she and Sinna had been all this time. And once they became gods together, these feelings only worsened. And so, as a capable Mage of Binding and Fracturing, they sought to do something about it, and after years of study performed a powerful ritual which trapped and sealed Sinna away and caused Shatu and the people of Lasra to forget all about him. His words and power twisted, he became vilified and referred to as the Lord of Darkness.

During Heart of the Total Eclipse, Sinna was freed and Shatu's memory restored.