Sithis is the God (But he isn't a god physically nor spiritually. It goes beyond that) of the Nothingness. And he is the Diety of Change and the Embodiment of The Void.
He is one of the 2 First Gods that are basically the first Actual Gods in The Elder Scrolls World.
Anuel is the God (Just like Sithis.He is not a god Physically Nor spiritually) of Order.
He is not Realy Descripted much in the Elder Scroll Games and not much is known about him..
Ok, For those who are wondering. They are neither Daedra nor Aedra. They are actually Gods of Gods. Dietys. They exist out of Physical and Spiritual Form. They are basically equal Forces. But they are total Opposites.
Anuel and Sithis are the form for the Physical and Spiritual Deminsions in the Elder Scroll Universe. In which. The Former Aedroth Lorkhan is responsible for Nirn. The planet which the Elder Scrolls takes place on (Mostly, Oblivion is actually the moons around nirn) The Universe is actually taken place in the void. Beyond the universe (Not the Void) Lies the home of the Aedra. And Immortals. Though Aedra unlike Daedra can die. Though not in the traditional Sense.
I gave you a lot of information in that post. Though i have confirmed all of it. They're might be some mistakes somewhere in that post.