Loyat was a Sith Lord of the Human species (female) and served as the apprentice to Darth Arho, a Dark Councilor, during the time of the Cold War.
Her training commenced on Korriban, where Loyat eliminated numerous other Sith trainees; however, she faced no repercussions because Darth Arho, who would eventually take Darth Baras's position on the Dark Council following his demise at the hands of the second Emperor's Wrath, chose her to be his apprentice.
During the latter part of the Galactic War, Loyat took part in the invasion of Ilum led by her master. Soon after, a Republic strike force engaged her in combat. Overconfidently, she proclaimed her intention to overwhelm them. She requested aid from Arho to eliminate the intruders, but her master did not respond. She was forced to fight them alone. Following a prolonged battle, Loyat was defeated and compelled to yield. Before being apprehended, she questioned the validity of Arho's teachings.