Darth Ruin (born as Phanius) was an Umbaran Dark Lord of the Sith who lived over twenty centuries before the Battle of Yavin.
An intelligent and charismatic renegade Jedi Master, Phanius was known for the disturbing tone of his philosophy, which included elements of moral relavitism and solipsism, possibly echoed in certain aspects by the much later Potentium.
Phanius abandoned his oath and left the order to pursue prohibited teachings, becoming one of the first to be known as the Lost Twenty. He secretly united the numerous Sith cults left over from the Great Sith War and other conflicts, and founded the New Sith Empire. In an event known as the Fourth Great Schism, fifty Jedi Knights soon followed him and pledged themselves to his new Sith Order.
The newly rechristened Darth Ruin and his followers initiated the New Sith Wars against the Jedi, but Ruin's Sith Order quickly disintegrated. Ruin was single-minded and his ambitions led to hatred and betrayal by his followers, who killed him.