Diogenes was born on a troop transport Sartorius in the screaming hell of a warpstorm near Cadia. Although the ship survived, multiple failures of the Geller field meant the ship was delayed for some months before limping to Prosan. Like many of his kin aboard the Sartorious, Valexos as a babe was carefully scrutinised for a number of years by Imperial forces before being released into the custody of his House. Or what was left of it.
House Valexos' fortunes had suffered greatly in recent years and there were whispers that all was not well in their palace upon Terra. Much of this was due to the machinations of House Bacchus, then a smaller House, who had ridden the Valexos coat-tails for years. Misinformation, blackmail, intrigue and corruption had brought House Valexos close to heresy. That all changed when Diogenes returned home: now a young man with title and a great deal of self-confidence the young Navigator had completed his training and looked to securing his birthright. Overnight a number of mysterious - if poetic - deaths rocked the Navigator community on Terra, as Valexos took revenge using what remained of his family fortune. After stamping out corruption in his House, he once again looked to the stars, taking a position as a Navigator on the Tranquility.
The Navigator's Curse has manifested itself profoundly in Diogenes' case. He is usually wrapped in a cape that has seen better days, and wears a suit of intricate enamelled white armour, with the design of a snake inscribed upon it, the snake's head forming the skull-like helmet he wears. He is a hulking individual and has a strange sinuous grace that most find disturbing. When not wearing armour he wears voluminous robes and a re-breather mask from the Adeptus Mechanicus. Ostensibly this is to help his breathing, but Valexos has no problems of that kind: in the privacy of his bubble, Valexos can at last reveal his true face. He still looks vaguely human, but with scaly skin, sharp claws and teeth, and a disquieting voice, the Navigator gene has turned him into at atavistic reptile in appearance.
Valexos, despite his appearance is quite an upbeat individual; he's pretty much invaluable to the ship and he knows it. A tad arrogant at times, he quite happily pokes fun at senior members of the bridge crew, including Sicarious; but knows when to shut up. Despite his forbidding aura and calculating nature he gets on with most of the bridge crew. He is generally left to his own devices, often preparing intricate charts of their Tranquility's travels. He has an interest in exotic weapons after acquiring a Dark Eldar Splinter rifle. His quarters are generally left empty for weeks on end as he spends most of his time in the Navigator bubble or accompanying Sicarious on one of his escapades.