During the Battle of Malachor V, a superweapon known as the Mass Shadow Generator was deployed.
This device harnessed the natural mass shadows emanating from planetary bodies. The gravitation irregularities present within the Malachor system, specifically at Malachor V, were exploited to unleash extreme destruction on anything located nearby. While engineered to capitalize on the unique gravitational characteristics of Malachor V, speculation arose suggesting potential modifications to enable its use in any star system. The Mass Shadow Generator possessed the capability to inflict severe damage or outright destruction upon ships and space stations orbiting the targeted planet, in addition to obliterating nearly everything on the planet's surface.
In 3960 BBY, the Zabrak technical expert Bao-Dur constructed the Mass Shadow Generator under the direction of Jedi Knight Revan. Revan intended for this weapon to serve as the linchpin of a trap designed to decisively conclude the Mandalorian Wars. Jedi General Meetra Surik, later known as The Exile, oversaw the weapon's activation. Revan strategically drew the Mandalorians to Malachor V, triggering a large-scale fleet battle in the planet's orbit. Amidst the conflict, Surik gave Bao-Dur a silent order to activate the secret weapon. Moments after, a large portion of both fleets were abruptly pulled into a massive gravity vortex, which crushed the countless ships into the planet's surface and fractured Malachor V to its core.
The event resulted in Malachor V becoming a shattered collection of planetoids, loosely held together by the system's gravitational anomalies. The wreckage of numerous Mandalorian and Republic warships orbited the broken remains of the planet. The planet's surface transformed into a desolate graveyard, filled with the echoes of thousands of fallen Jedi, Republic soldiers, and Mandalorians. Destroyed vessels littered the landscape, and the only surviving inhabitants were dangerous storm beasts.
In 3951 BBY, the Mass Shadow Generator was deployed for a second and final time. During her campaign against the Sith Triumvirate during the First Jedi Purge, Surik journeyed to Malachor V in pursuit of the Sith Lord Darth Traya. She engaged the Sith forces occupying the planet at the Trayus Academy, defeating both Darth Sion and Darth Traya in combat. Shortly thereafter, Bao-Dur's remote activated the Mass Shadow Generator, causing the gravity field's sudden release to destroy what remained of the planet.
Circa 3625 BBY, during the Third Galactic War between the Galactic Republic and the reconstituted Sith Empire, a secretive Sith cult known as The Unmasked reconstructed the Mass Shadow Generator within Sector R-4. Lady Dominique, the cult's cybernetically enhanced leader, sought to merge her consciousness with the Mass Shadow Generator in order to control the superweapon. Before the Mass Shadow Generator could be re-armed, a strike team, including the Commander of the Eternal Alliance, intervened to stop the Unmasked and destroy the superweapon once more.
In a non-canonical scenario, if the player aligns with the dark side, G0-T0 destroys the remote, preventing the second activation of the Mass Shadow Generator.
While Timeline 9: The Mandalorian Wars indicates that Revan, not Surik, activated the Generator, this is not necessarily a retcon. The Timeline series is presented within the universe as the Jedi's preferred historical narrative.