Sithis (or Padomay) is the embodiment of primordial chaos. It is the patron of the Dark Brotherhood and the God that many members of the group worship, and it is they who give it a male persona, saying he is the husband of the Night Mother, and the father of her five children, who she killed in his honor. Sithis is an equal and opposing force to Anu, with whom he battled at the dawn of time over their joint creation, Nirn. Although the Dark Brotherhood refer to Sithis as a Dread "Father", they recognise that he is not an Aedra, and nor does he hold a plane of a Daedra in Oblivion. He has a place in nearly all the creation myths of Tamriel, under many different names and guises. Although different tellings change whether Sithis or Anu came into being first, most tell that Anu is responsible for the creation of the Aedra, and Sithis is the creator of Lorkhan, and therefore is the progenitor of all mortal creation due to his creation of Lorkhan. Some lore also suggests that the Daedra may be "of Sithis' blood", which is supportive of the nature as beings of change.
Sithis has an interesting relationship with other spirits. Sheogorath is described as the "Sithis-shaped hole" of the world, which is probably a reference to Sheogorath's chaotic nature as the Daedric Prince of Madness. His connection with Mephala is a confused one, in some instances he is her child, others say he is another form Mephala can take and others suggest he is older than Mephala, which most in-game lore supports.
In adition to being the patron God of the Dark Brotherhood, almost all Races of Tamriel recognise Sithis in some form, and even the mysterious and sentient Hist trees recognise him. The Argonians also have a strong connection with Sithis in their Shadowscale tradition: Every Argonian born under the sign of the Shadow is presented to the Dark Brotherhood at birth and is trained to be an Assassin. If they then reach a certain age, they enter the Dark Brotherhood in Sithis' service.