I started with the Vostroyan officer with a Power Sword and Plasma Pistol. To represent his bionics I replaced one foot with a with the foot of a necron warrior. For his power sword arm, I used the bionic arm from the Space Marine captain sprue. I cut off the chain-sword blade with the original Power Sword blade from the Vostroyan offfcer model. Since Straken also carries a shotgun, I added an Empire repeater handgun to represent the shotgun; I think it gives a nice Steam-punk look that I've always associated with Vostroyans.
And finally a few pics of the Colonel all painted up.