Who is Darth Revan?

Darth Revan:

Following the Sith War and the fall of Exar Kun , the Republic was at its most vulnerable state. Sensing this weakness, the warlike Mandalorians began a series of brutal attacks against worlds throughout the Outer Rim. In desperation, the Republic turned to the Jedi Council for aid. The learned Masters wanted to proceed with customary caution and due care before embarking on a long and destructive military campaign; however, more immediate help came in the form of two young Jedi Knights named Revan and Malak. Ignoring the dictates of the Jedi Council, the charismatic pair recruited many to their cause, rallying the impulsive youth of the Order with cries of victory and glory. With Revan and Malak at the head of their great fleet, the Republic set forth to drive the invaders back. The Mandalorian Wars were long and bloody, and many Jedi perished in the struggle. Yet, at its end, the Republic emerged triumphant, and Revan and Malak were hailed as heroes. But the heroes did not leave the war untouched; something about the Outer Rim worlds twisted and corrupted them. On Korriban, Revan uncovered the lost secrets of the Sith and became the heir to an ancient and evil legacy. Succumbing to the lure of the Dark Side, the fallen Jedi assumed the title of Darth Revan, Dark Lord of the Sith. Revan's friend Malak grudgingly took the mantle of the Dark Lord's apprentice. The great fleet under their control abandoned the Republic and swore fealty to their new Sith masters. With their army of followers, Revan and Malak returned not as saviors, but as conquerors. For two years battles raged on the perimeters of Republic space. The Sith gained victory after victory, until the Jedi set a trap to capture Revan and Malak. But during the chaos of battle, Malak turned on his master and tried to destroy both Revan and the Jedi, but his plan failed. Revan was captured by the Jedi, while Malak escaped and proclaimed himself the new Dark Lord, swearing revenge on the Jedi and Revan. But the Jedi had other plans. They used the brain-washed Revan to help track down Malak. On the ancient Star Forge station, Master and former-apprentice faced off one last time, ending in Malak's defeat. Having regained his memory and the title of Dark Lord, Revan renewed his crusade against the Jedi. Just as the Sith were nearing victory, having nearly wiped out the Jedi, Revan mysteriously left his Sith followers to hide in the Unknown Regions, never to be seen again. The Jedi Civil War would drag on for years to come, the Sith hunting down the Jedi and the Jedi managing to survive.