Yavian Suster is a corporal serving as permanent training staff at Camp Camillion, a MAGA facility maintained on the surface of Guathelia. He is seconded there from the 2079th Battalion (→LOTD).
When the camp was attacked in 3745 ELC, during what is now known to be an offensive connected to the Shaeld Hrathan invasion, he was the only person known to have escaped both death and capture. He was later found by Private Junn Delanka.
Suster gave some details of the initial attack on Guathelia: that the gate had stopped responding during a briefing with MAGA Command, that the ICS Vehement had sent a chaotic transmission before falling silent, and that the orbital strike on the capital's defences had been audible from Camp Camillion. He also confirmed that the tactical fighters seen by Omin Volkas came from the camp, and that they did not return.
When Halfre Blesson pointed out that she had seen only eighteen bodies from amongst the two battalions posted to Camp Camillion, Suster was visibly shocked. It can be inferred that the piece of debris which knocked him out did so early on in the attack.
Suster disappeared while Delanka, Halfre, and Omin were absent from the camp. He was later located by Delanka, in the midst of a group of Rasas who appeared to be defending Shaeld Hrathan grounding splinters. Delanka's conversation with Suster was enough to convince him that the corporal was no longer in his right mind.
It is open to speculation as to how Suster was turned into a Rasa. What is clear however, from comparisons with Omin, Halfre, and Delanka, is that the process can take different periods of time for different people. Observations by Elm Caden and Occre Brant would appear to account for that difference (→TRD).