Colonel Tildnis was a Kilji who served the nation of the Kilji species, the Kilji Illumine. He was the commander of the Kilji picket cruiser Hammer, one of the two cruisers of Illumine General Crofyp's task force, the other being Crofyp's Kilji war cruiser, Anvil. In 18 BBY, the task force was dispatched to the Unknown Regions Rapacc system by "Jixtus," a Grysk agent who had allied himself with the ruler of the Illumine, Generalirius Nakirre.
In the system, Tildnis and Crofyp attempted to capture refugees hiding on the planet Rapacc; however, their efforts were stopped by the Paccosh-commandeered Nikardun blockade frigate Aelos and the Chiss heavy cruiser Springhawk. Crofyp was killed after the Springhawk destroyed the Anvil, and the Hammer fled to the Unknown Regions Sunrise system. The picket cruiser kept station with a Grysk vessel there until the Aelos tracked down the Kilji cruiser. The blockade frigate's crew then boarded the Hammer and killed all Kiljis aboard, including Tildnis.
Tildnis was a Kilji officer who served as a colonel in the Kilji Illumine, the nation of the Kilji species. He commanded the Kilji picket cruiser Hammer, one of the two cruisers that formed Illumine General Crofyp's task force; the other was Crofyp's Kilji war cruiser, Anvil. In 18 BBY, Crofyp's task force was dispatched to the Unknown Regions Rapacc system by the Grysk operative known as "Jixtus," who had allied himself with the ruler of the Illumine, Generalirius Nakirre. The Grysk tasked the Kiljis with capturing a group of refugees that was hiding on the planet of Rapacc. Jixtus also hired two Pathfinder navigators, Sarsh and Qilori, to navigate for the Hammer and the Anvil respectively.
The Chiss heavy cruiser (one such vessel pictured) Springhawk fought Tildnis's Hammer and Crofyp's Anvil in the Rapacc system.
Tildnis's cruiser slowed down as it traveled to the Rapacc system, but it was able to catch up with Crofyp's cruiser after Qilori ceased the latter vessel's journey. The vessels then arrived in the inner Rapacc system simultaneously. The Kiljis were confronted by the Paccosh-commandeered Nikardun blockade frigate Aelos. Crofyp issued Paccosh Commander Uingali foar Marocsaa, the Aeloss captain, a directive to allow his forces to retrieve the refugees they sought. As Marocsaa did not comply, the Kilji general prepared a cross-fire attack on the Paccosh blockade frigate. Crofyp's servant, Vassal Four, signaled Tildnis to move his cruiser along the Aeloss portside while the Anvil did likewise along the frigate's starboard. Once the Kilji task force was in position, the Chiss heavy cruiser Springhawk arrived in the outer system, firing two ship-disabling plasma spheres at the starboard of Crofyp's flagship before joining the confrontation in the inner system.
After the Chiss commander, Senior Captain Mitth'raw'nuruodo, core name "Thrawn," instructed the Kiljis to move clear of the Aelos, Crofyp had his and Tildnis's vessels trade fire with the Springhawk. Shortly after, Thrawn's plasma spheres paralyzed the Anvils starboard, and Crofyp moved his flagship's paralyzed side to shield the Hammer from the Chiss attack so the picket cruiser could escape. While Tildnis and Crofyp had a loud conversation through comm, Qilori escaped the Anvil aboard an escape pod. The Hammer escaped to the Unknown Regions Sunrise system and the Anvil was destroyed by the Springhawk, killing the war cruiser's commander.
Senior Captain Thrawn (pictured) boarded Tildnis's cruiser.
While Tildnis traveled to the Sunrise system, Thrawn rescued Qilori. The senior captain brought the navigator aboard the Aelos and commanded him to use the Force to track down Sarsh and the Hammer. Hours after the picket cruiser arrived in the Sunrise system, where it kept station with one of Jixtus's Grysk vessels, the Aelos arrived. Marocsaa claimed the Chiss were chasing him and asked the Hammer for protection and a safe haven.
In response, the Grysk warship's commander discussed Tildnis and the Aeloss presence at Sunrise with Marocsaa. The Paccosh told the Grysk that he thought very little of a commander that ran from battle. The Grysk then acceded to providing the Paccosh with a safe haven, directing the frigate to the Hammers portside. After the Kiljis tried to position the Aelos near the picket cruiser's tractor beam projector and below its portside weapons cluster, the Paccosh disabled the Hammers tractor beam projector with a Crippler net weapon and boarded Tildnis's cruiser.
Marocsaa, Thrawn, Qilori, and a squad of Paccian commandos killed all the Kiljis aboard the picket cruiser, including Tildnis. The commandos left the colonel's corpse on his warship's bridge. Once the group left the Hammer with Pathfinder Sarsh, the Grysk warship destroyed the Kilji vessel and escaped into hyperspace.
As a servant of the Illumine, Tildnis was enlightened to the Kilji religion. When Qilori saw the colonel's corpse, he thought he would not face any awkward questions from Tildnis regarding his presence aboard Marocsaa's frigate.
Tildnis's corpse appeared in the 2021 novel Thrawn Ascendancy: Lesser Evil, the final installment of Timothy Zahn's Star Wars: The Ascendancy Trilogy.