General Onator was a senior Imperial military commander who served under both Warmasters Slaydo and Macaroth during the Sabbat Worlds Crusade. Onator was slain on the world of Parthenope in 767.M41 when his Astra Militarum forces were cut off, surrounded and ultimately annihilated by the Forces of Chaos loyal to the Magister Qux of the Eyeless.
General Onator was involved in one of the worst defeats for Imperial forces during the entire Crusade. Onator and his troops met their ultimate fate on the fiercely contested world of Parthenope in 767.M41. One of Archon Nadzybar's most notorious Magisters, Qux of the Eyeless, was the architect of this disaster for the Emperor's servants.
After the crushing defeat suffered by the Forces of Chaos at Balhaut in 765.M41, Qux's forces had withdrawn from that system and re-consolidated upon the contested world of Parthenope. The Crusade's High Command charged General Onator, commanding 20 divisions of the Imperial Guard, to retake this world. Some Imperial scholars believe that Onator may have been complacent following the great victory at Balhaut only two years earlier, and that he believed the Chaotic forces' morale and will to fight had been effectively broken. If so, it was a misjudgment that was to have terrible consequences.
Magister Qux ordered a feint, and his troops' line appeared to collapse under the initial Imperial assault, but this was merely a ruse. Coaxing the Imperial troops into an advance across the Caterad Highlands, the Magister's forces then encircled and outflanked Onator's troops. Beset from all sides, Onator sent desperate astropathic requests for assistance, and began the attempted withdrawal of his forces down from the Highlands and into the towns of Toronon and Ceylask.
A single Imperial Guard division, comprised of the Samothrace 4th, the 2nd Mnenomite and the 23rd and 26th Baldackian Fusiliers regiments, found itself cut off from the rest of the retreating force. Standing their ground in the Besh Valley, the valiant Guard division was annihilated by a sustained five-hour Chaotic artillery bombardment.
Onator managed to secure Toronon but failed to hold onto Ceylask, which the Magister's forces savagely razed during their advance. Onator's troops were besieged for three solar weeks at Toronon. Their hopes were temporarily raised when the Adeptus Mechanicus managed to send in support in the form of Titans, but these were soon dashed as Qux utilised a large number of Chaos war engines provided to him by one of the Traitor Titan Legions.
The Mechanicus reinforcements were utterly destroyed after a ferocious nine-day battle and Onator's troops were ultimately slaughtered to the last man, many fed as living sacrifices to the hunger of the Blood God Khorne. The details of the final fate that befell Onator and his remaining troops were quickly suppressed by the Inquisition for morale reasons.
- Sabbat Worlds Crusade (Background Book), pg. 59