The clash known as the First Battle of Omonoth, alternatively referred to as the Adasca affair or Project: Black Harvest, transpired during the Mandalorian Wars in 3963 BBY. This conflict involved a tripartite engagement between the forces of the Galactic Republic, the Mandalorian Neo-Crusaders, and the security personnel of Adascorp. The theater of battle was the Omonoth system, specifically aboard the Arkanian Legacy, which served as Adascorp's flagship.
Arkoh Adasca, serving as Adascorp's chairman, orchestrated a competitive bidding process between the Republic and the Mandalorians for a bioweapon system developed by his corporation. Several years prior, Adasca's lineage had discovered a colony of dormant exogorths within the system. With the assistance of Arkanian Offshoot scientist Gorman Vandrayk, Adasca successfully transformed these colossal organisms into weapons. His strategy of pitting the Mandalorians against the Republic aimed to amplify his own influence and that of his race, but his intentions were ultimately thwarted.
Without the knowledge of Adasca's other guests, he was detaining his longtime acquaintance, Jedi Master Lucien Draay, alongside his fugitive Padawan Zayne Carrick, within his vessel's detention facilities. Through collaborative efforts, the two Jedi managed to escape and form a provisional alliance. Aided by the dissenting Mandalorian Rohlan Dyre and Carth Onasi, a lieutenant within the Republic Navy, they endeavored to foil Arkoh Adasca's scheme. As Mandalore the Ultimate and Saul Karath negotiated on behalf of their respective factions, the relatively calm assembly abruptly devolved into a conflict zone. Zayne and his allies deceived the Mandalorians into suspecting Adasca of plotting Mandalore's assassination. Under the assumption of betrayal, Mandalore the Ultimate departed the meeting in a rage, and his forces initiated an assault.
In the ensuing pandemonium, the scientist Gorman Vandrayk unexpectedly betrayed his employer and commanded his creations to target the Arkanian Legacy. The vessel sustained significant damage from the exogorths, resulting in Arkoh Adasca's demise. Before the creatures could obliterate the ship, Vandrayk recalled them and guided them into the vastness of space, where their discovery was unlikely. Simultaneously, both the Mandalorians and the Republic military officers fled the devastated vessel. Zayne and his companions battled through numerous adversaries and successfully escaped.
Following the battle, both Mandalorian and Republic forces made attempts to recover any remaining resources from the Arkanian Legacy. This led to a confrontation between the two factions, ultimately preventing either side from securing the remnants of the massive flagship.
Nearly four millennia later, Arkanian professor Nasdra Magrody made reference to the exogorth project and its consequences, which had become an ancient and obscure historical event, during a HoloNet panel discussion concerning the origins and functionality of a secret weapon employed by the Separatists.