Loyat was a female Human Sith Lord who was the apprentice of the Dark Councilor Darth Arho during the Cold War.
When Loyat began her training on Korriban, she killed several other Sith, but was never punished for it when Darth Arho, who would later ascend to Darth Baras's seat on the Dark Council after his execution by the second Emperor's Wrath, selected her as his apprentice.
In the later stages of the Galactic War, Loyat participated in her master's invasion of the planet Ilum. She was soon confronted by a Republic strike team. She arrogantly boasted to her opponents that she would crush them. She called on Arho to aid in destroying the interlopers but her master did not come to her, so she fought her opponents regardless. After a long duel, Loyat was beaten and forced to surrender. She then questioned Arho's teachings, before she was taken into custody.
Loyat first appears in the Star Wars: The Old Republic as the apprentice of the Darth Arho. After defeating her, the player has the option of either executing Loyat or arresting her.