Thanks for the fantastic replies so far, Heretics!
I think I'm getting a bit confuse with my fluff which is making my theme a bit less focussed (although what's been offered so far has been ace). Is the Red Duke actually anything to do with Mousillon or was he buried in a different place? In fact, was he even Brettonnian? I know he came down with a bad case of the Vampires after his body was brought back from a Crusade on Araby, but was he a Brettonnian Duke or an Empire Knight?
Should the Red Duke be from somewhere else, then Stephen_Newman's list really comes into effect. I might add a Coven Throne, with the reason being that the Lahmians like the idea of a Duke, even if he doesn't have a Dukedom. Being on Crusade in Araby, he could conceivably have travelled near to Lahmia, maybe even a Lahmian being the one to give him the Blood Kiss.
should Mousillon also be seperate to the Red Duke, then I can see that force being more with the Necromancers and the more 'risen graveyard' feel- Mortis engine, Hexwraiths, Ghouls and some Zombies.
Which idea do you reckon would have the stronger theme-idea driving it?