A sector existed in the northeast-zenith region of the Chiss Ascendancy. Within this sector were the Ornfra system and the planet known as Ornfra. During 18 BBY, as a crisis unfolded within the Ascendancy, two separate engagements took place in this sector. The initial event involved a short confrontation in the Ornfra system. The Chiss Expansionary Defense Fleet warship Grayshrike, the Clarr family light cruiser Orisson, the aggressive Grysk species, and the Dasklo family were all involved. Not long after, the Orisson was ambushed by the Grysk Shatter-class WarMaster FateSpinner as the Orisson made its way back to the system.
The Ornfra system, along with the planet of Ornfra, was situated in a sector located in the northeast-zenith of the Chiss Ascendancy. Ornfra had significant economic and political importance within the sector. Consequently, all of the Ascendancy's Nine Ruling Families, along with seventeen of the forty Chiss Great Families who had aspirations of joining the Nine, maintained strong presences on the planet.
During a period of crisis in the Ascendancy, specifically in 18 BBY, the sector was the site of a skirmish that involved four distinct factions. The Clarr family warship Orisson aimed to destroy a Grysk asteroid missile platform that was disguised as a Mitth family espionage station and was controlled by a Grysk freighter within the system. The warlike Grysk species sought to incite a civil war in the Ascendancy. The Dasklo family defended Ornfra. The Chiss Expansionary Defense Fleet warship Grayshrike was assigned to Ornfra to prevent conflict between the Clarr and Dasklo families. As a result of the skirmish, the Defense Fleet successfully convinced the Clarr of the asteroid missile platform's true nature. The station then self-destructed, also destroying the Grysk freighter.
Shortly thereafter, Patriarch Clarr'ivl'exow "Rivlex" of the Chiss sent Captain Clarr'os'culry "Roscu" and the Orisson back to the Ornfra system to conduct an investigation. The Grysk agent "Jixtus" had alleged that the Dasklo family was producing warships that were disguised as vessels belonging to other Chiss families. Upon the Orisson's arrival, it was ambushed by Jixtus's flagship, the Shatter-class WarMaster FateSpinner, who had been informed of the Chiss vessel's expected arrival. The Orisson fled into hyperspace after a brief engagement.
The northeast-zenith sector of the Chiss Ascendancy was initially introduced in the 2021 novel titled Thrawn Ascendancy: Lesser Evil. This novel served as the concluding part of The Ascendancy Trilogy and was authored by Timothy Zahn.