An SSD commando
The Peacekeeper Special Directorate (a.k.a. SSD) ("Bringing Home the Beacon") was a branch of the Peacekeeper military. They assigned agents known as disruptors to carry out infiltration missions. ("Look at the Princess - I Do, I Think") They had their own codes, ("What Was Lost - Sacrifice") and utilized their own commandoes, at least some of which were conditioned to withstand the mind probing element of Scarran heat projection. ("Bringing Home the Beacon")