Malachor V
A graveyard world resonating with the dark side of the Force, Malachor V is where the most terrible atrocity of the Mandalorian Wars took place. Malachor was a world taboo in Mandalorian culture, something the fallen Jedi Darth Revan used against them in order to win the war. Revan amassed an enormous fleet (composed of Jedi and Republic soldiers whose loyalty to Revan was in question) and sent it to the planet, providing the Mandalorians with a target too good to pass up. In a heated space battle that would determine the fate of the Mandalorian wars, a Republic force led by the Jedi Exile was commanded to attack the Mandalorian fleet orbiting Malachor V. With the full force of the Mandalorian neo-crusade arrayed against the Republic fleet the collateral damage was staggering. With the titanic battle at a brutal stalemate the Jedi Exile was prepared to seize any opportunity to end the war. With war's end one victory away The Jedi Exile unveiled the Republic's secret weapon: the Mass Shadow Generator. Issuing the command to activate the Mass Shadow Generator, a weapon developed by Iridonian Zabrak engineer Bao-Dur, the Jedi Exile unleashed devastation that literally crushed all participants - Mandalorian, Jedi, and Republic soldier alike. Malachor was nearly wiped out, as upon its surface countless beings died in a cataclysmic explosion that engulfed the planet. In the resulting destruction, almost the entire Mandalorian fleet was obliterated—as well as many Republic vessels. Left orbiting the planet was the wreckage of countless Mandalorian and Republic warships. All that remained on the surface was a desolate graveyard echoing with the deaths of thousands of Jedi and Mandalorians, littered with destroyed ships, and inhabited by vicious Storm Beasts. The survivors of the Battle of Malachor were few, but most were fated for legendary status: Carth Onasi, Canderous Ordo, Bao-Dur and most telling of the atrocities of the battle, Darth Nihilus and the Jedi Exile.
The concentrated deaths of so many Jedi, Mandalorians, and Republic soldiers all at once sent a powerful shockwave throughout the Force, resulting in the Jedi Exile purposely severing all ties with the Force. It was Malachor that marked Revan's final descent into darkness, a journey that would at last be completed when the former Jedi hero declared himself Dark Lord of the Sith. His fall sent one of his Jedi teachers, Kreia, in search of answers. She found them at the Trayus Academy.
From the ashes of Malachor V arose three immensely powerful Sith Lords: Darth Nihilus, Darth Traya, and Darth Sion. They nearly brought about the complete destruction of the Jedi Order. Their plans were foiled by the Jedi Exile.