This person was a Human male who was banished to the Undercity on the planet of Taris, a city-covered world, because he committed crimes against the Taris government. Rukil was his son.
Although he belonged to the Outcasts, he, his father, and his son believed they could escape their neglected existence by discovering the Promised Land, a belief many other Outcasts doubted. Learning that his father disappeared while searching for evidence, he began his own quest to locate the Promised Lands. He followed his father's path, discovering additional evidence which he recorded in a journal. However, he never shared this with the Outcasts because rakghouls attacked and killed him, and both journals vanished into the Undercity sewers.
His son, Rukil, continued the search, yet he made no progress and failed to recover the journals of his father and grandfather. Eventually, old age forced him to abandon the quest, and he hired Malya to continue it. Malya discovered proof that Rukil's father and grandfather had accessed the lower sewers of Taris, noting it in her journal. Unfortunately, she also fell victim to rakghouls and never returned with the information. Revan was enlisted by Rukil to find her in 3956 BBY, and it was not until then that Rukil learned of this. Revan successfully found all three journals during the search and gave them to Rukil.