First up is the Rogue Trader him/herself! My favorite thing about this one is the "Loaded for Zoat" ability. The Inquisitors all have a keyword that they hate, and I thought it'd be fun for the Rogue Trader to have a personal problem with Monsters. Of course, their real strength lies in the Warrant of Trade, which allows the Rogue Trader to bribe enemy units into submission!
Rogue Traders also get the same Allegiance treatment as the Inquisitors. They plunder all over the galaxy and so can take Command Traits and Artefacts from any army!