Silon is former Battlefleet Calixis fighter pilot that was grounded on the main Navy orbital above Vaxanide after one too many incidents related to insubordination or getting into fights with other pilots and ground-crew. Only an exemplary fight record, including his triple-ace status, prevented the Navy from booting him out altogether. In his new capacity as a naval security officer it didn't take Silon long to become involved in contraband transshipment between Vaxanide and visiting starships. It might have gone undetected forever had they not got dragged into dealing with more and more dangerous, until finally they were moving rogue psykers. The Inquisition moved on the operation in force and Silon was picked up for questioning.

Xerza quickly discovered that Silon was a psyker – or rather he's an anti-psyker., a null-psi, an untouchable. Such persons are exceedingly rare; only one in one billion people posses this special mutation, and of those only a very few are actually detected and recruited. Such untouchables are virtually immune to direct psychic manipulation. The downside is that normal people (for psykers its even worse, a sense of physical illness cause by being close to them) feel alienated from them; they can sense that something isn't quite right.

Silon is tall and dark and quite handsome. He would undoubtedly be popular with the girls were it not for his untouchable aura. Actually he still is quite popular, it just never works out for him in the long run, and he's resigned himself to a life of endless underground parties and casual relationships of the carnal kind.

Silon is also a superb shot, even with personal weapons, but his true forte is as a small-craft pilot – despite his dodgy military record he was in fact one of the finest fighter pilots in Battlefleet Calixis and his years in naval security allowed him to practice flying many other small-craft.