Board Thread:Lore Discussion/@comment-85.87.179.48-20130620091301/@comment-9887604-20130705173459

That is from the Annotated Anuad Exploding Dovakhin, Sithis, Anuriel, and Auriel come from the Monomyth which includes the elvish creation myth. Sithis is the elvish version of Padomay, it is a slightly different view of creation. I quote

"In most cultures, Anuiel is honored for his part of the interplay that creates the world, but Sithis is held in highest esteem because he's the one that causes the reaction. Sithis is thus the Original Creator, an entity who intrinsically causes change without design." Monomyth

"Anu encompassed, and encompasses, all things. So that he might know himself he created Anuiel, his soul and the soul of all things. Anuiel, as all souls, was given to self-reflection, and for this he needed to differentiate between his forms, attributes, and intellects. Thus was born Sithis, who was the sum of all the limitations Anuiel would utilize to ponder himself." Monomyth

Sithis is by definintion the ability to gain perspective. Anu is the is, Sithis is the is not, without the ability to compare 1 against 0 you would never know what 1 really is.