Deceased (3,956 BBY)
Malak claimed the title Dark Lord of the Sith after the Jedi attacked Revan. However, Revan survived the attack. Soon thereafter, Malak sent bounty hunters and even his own apprentice, Darth Bandon, to finish what he had started, but Revan proved more than a challenge for the Sith. Malak was eventually killed by a redeemed Revan during the Battle of the Star Forge.
Knights of the Old Republic
Malak was the apprentice of Darth Revan prior to the Capture of Darth Revan. When a Jedi strike team boarded Revan's flagship, Malak fired on the ship's bridge, intending to kill both his master and the Jedi aboard. After this event, Malak took the mantle of Lord of the Sith.
Malak continued to fight against the Galactic Republic and pursue the Jedi knight known as Bastila Shan, whom he thought he could turn to aid him in the war. In 3956 BBY, Malak assaulted the Endar Spire over Taris, with Bastila aboard. When Bastila escaped the attack by taking an escape pod to the surface of the planet, Malak moved his search there. After some time, however, Malak decided that he could not risk Bastila escaping again, and so ordered his orbiting fleet to bombard the occupied planet, killing both civilians and his own soldiers.
Once again, however, Bastila escaped Malak, this time aboard the Ebon Hawk, fleeing to Dantooine. Admiral Karath brought Calo Nord, a bounty hunter, to Malak. Calo informed him that not only that Bastila escaped, but also that she was traveling with war-hero Carth Onasi, and his former master, Darth Revan, who had a new identity forced onto him by the Jedi Council after Bastila rescued him from his crippled ship.
Malak sent Calo Nord after the group in order to eliminate them, but his attempt failed. Realizing that he underestimated the new Revan, he sent his apprentice, Darth Bandon, to kill Bastila and Revan. However, Bandon too was defeated. Shortly thereafter, however, the Ebon Hawk was captured by the Leviathan, the flagship of Admiral Saul Karath. At this point, Malak had ordered the destruction of the Jedi Enclave on Dantooine in order to prevent Bastila and Revan's return, as well as to remove some resistance against his conquest. When Malak arrived at the ship, he found that Bastila and Revan had escaped their holding cells, and confronted them on their way to the hanger. He fought briefly with Revan, but then was interrupted by Bastila, allowing his former master to escape to the Ebon Hawk.
However, he had finally captured Bastila, whom he took to the planet Rakata Prime to torture. He corrupted Bastila and turned her to the dark side of the Force, making her into his new apprentice to replace Darth Bandon. Malak then returned to the Star Forge to oversee its operation, and to wait for Revan to confront him there. When Revan did arrive, his ordered all of his troops on the station to attack him in order to slow Revan and give him enough time to prepare the Star Forge's defense systems. Managing to activate the defenses, he loosed a number of powerful droids on Revan, but they were easily defeated by the former Sith.
Malak was then confronted by his former master in one of the station's observation rooms, in which he kept Jedi from Dantooine barely alive in stasis so that he could harvest their power. Here, he fought with the redeemed Revan for the final time, and was defeated, despite the dark side energies of the Star Forge feeding his power.