Chaos god of the ancient sith, and father-mother of the pantheon. In keeping with Sith tradition, the male pronoun is used for him-her.

This protean, tentacular hermaphrodite is the source for the sith gods. His first child was Bellisarius, who immediately tried to usurp (or perhaps just imprison for torture) Anu. As Anu battled against Bellisarius, he grew angry at the pain inflicted against him and Der-ak was born. With Der-ak's help, they were able to overcome Bellisarius for a time, but he always returned stronger than before.

Third to be born was Kothar, the crafter. After their battle, Anu and Der-ak each turned and walked in opposite directions. They each sought to conquer heaven, with Anu conquering the left half and Der-ak the right. While he travelled, Anu came upon a skilled family of smiths. Anu demanded that they serve him, but the proud father of the family refused. Anu promptly ate them and found himself pregnant. One day, Anu and Der-ak met after each conquering half of heaven. Der-ak stole away Kothar, and forced him to forge weapons and armor that he might defeat their father. Kothar had little choice, so he made for Der-ak a mighty blade. Der-ak took up this mighty sword and used it to cut a piece from Anu.

It was at this time that Bellisarius returned for the first time. He struck out at Anu's wound, and Anu lashed out at Anger. Kothar worked furiously upon the piece which had been cleft from Anu, drawing determination from the chaos, pain, and anger around him. The piece became Horon, the dead god. Horon was able to put Bellisarius into his grave, and Anu sealed the dirt with his sperm and blood.

The tomb of Bellisarius grew hungry for more blood, and Geb was born.

This constant struggle for dominance against Pain characterized the First Sith Myth Cycle.

(suggestion from adrian: Pain is part of the struggle to dominate; if you dominate your pain you can dominate your enemies, therefore Bellisarius is the beast against which the rest of the Pantheon struggles (when they're not fighting each other)