The Syndic Mitth'raw'nuruodo training academy functioned as a military educational institution for the Chiss Ascendancy. It was situated on the frigid planet of Rhigar, found within the Rata Nebula. The nebula itself existed within the Unknown Regions, specifically in the region under the control of the Chiss Ascendancy. As allies of the Chiss, the Empire of the Hand also utilized this school. The facility was composed of a singular, enormous dome, concealed within the frozen landscape of the planet. Inside, it housed resources such as a shared dining hall and hangars for Clawcraft starfighters, all arranged around a sizable central area featuring an interior forest.
The academy gained notoriety for imparting to its students the contentious philosophies of the exiled Syndic Mitth'raw'nuruodo—more widely recognized as Thrawn, the Galactic Empire's Grand Admiral and Warlord. Despite this, the academy doesn't appear to have been integrated into Thrawn's own Household Phalanx, which operated outside Chiss territory in conjunction with the Empire of the Hand, because the academy's leader held a higher rank than the Household Phalanx's commanding officer.
Instead, it seems the academy was officially just one of many military schools within the Chiss Ascendancy's structure. Its dedication to Thrawn was secret, intending to cultivate a "hidden phalanx" of supporters within Chiss territory. These individuals would, either knowingly or unknowingly, back military and political actions aimed at furthering Thrawn's objectives, many of whom would be unaware they were deliberately being manipulated to support the coup.
Whether the academy was affiliated with the Chiss Expansionary Defense Force or a specific Colonial Phalanx or Ruling Family remains unclear. Nevertheless, despite its clandestine role in advancing Thrawn's agenda, prominent figures within the Ascendancy evidently maintained some degree of authority over the institution, or at least believed they did. When Imperial General Baron Soontir Fel engaged in diplomatic discussions with the Chiss leadership, sometime before 19 ABY, his son Davin was dispatched to the academy as a guarantee of his father's allegiance. Following Davin's heroic death in battle, his younger brother Jag took his place at the academy.
By 19 ABY, the academy was under the command of a male Chiss named Gimald Nuruodo, with First Lieutenant Shawnkyr Nuruodo serving as the cadet commander. In that year, the academy suffered an attack, purportedly by the Cavrilhu Pirates, resulting in the deaths of Commandant Gimald and seemingly also Phalanx Commander Kres'ten'tarthi. Jag and Shawnkyr united the cadets, successfully repelling the pirates—an event that led to Jag's promotion to cadet commander, replacing Shawnkyr.
Following his training, Jag joined a Colonial Phalanx within the Ascendancy, before defecting to the Household Phalanx alongside Shawnkyr. The academy's continued operation after the raid and the betrayal of its location is uncertain, but by 28 ABY, Jag could reference multiple "academies" loyal to the Household Phalanx.
The designation "Syndic Mitth'raw'nuruodo training academy" originates from the novel The New Jedi Order: Dark Journey. While it's unlikely to be the academy's official title, it stands as the sole specific name used to refer to the facility within Star Wars canon.
Some ambiguity exists regarding whether the attack on the academy transpired in 19 ABY or 22 ABY. The primary issues with the earlier date involve the assumption that Jag was born around 8 ABY, making him only eleven at the time, rather than the stated fourteen, and the appearance of Stent alive (albeit in a holoprojector transmission) in Survivor's Quest, set in 22 ABY.