Remember that line from the cover of the Radical's Handbook (Dark Heresy)?
I've come to see that while I love the mechanics of Black Crusade - even over Only War - I don't really want to run a game of cartoonish over-the-top villains. I do want to use the Black Crusade ruleset and the Screaming Vortex setting, but I want to take a different angle. I'm thinking of having the Heretics (PCs) actually be Acolytes/Throne Agents of a radical Inquisitor of the Xanthite faction (and no, I have no interest in trying to do this Dark heresy rules, especially not the Ascension rules).
For those that don't remember, Xanthites are the radicals that believe that the best way to fight Chaos is by using the tools of the Warp against it. So we have a group of (anti-)heroes sent into the Screaming Vortex by a 'crackpot' Inquisitor that believes that a great threat will emerge from it and strike out against the Calixis Sector (keeping in mind that very few know of the threats within the Screaming Vortex). This group is expected to infiltrate and destabilize the factions existing within the Vortex by any means at their disposal. They are not really expected to have any further contact with their Inquisitor once they cross into the Vortex.
The characters will operate in all ways as Black Crusade characters (including using Infamy - their actions can still mysteriously please the Ruinous Powers) except that their goals will be to prevent any factions from leading a Black Crusade out of the Screaming Vortex. Compacts within the group will be unlkely to be dedicated to any particular Chaos God and most characters will struggle to remain Unaligned. I will allow the characters to spend Infamy to reduce Corruption (per the GM Kit rules) since neither Ascension or Spawndom is going to be desireable. This is intended primarily for human characters, but it's possible that some disgraced 'renegade' Astartes might be able to be a part of it as well.
Any constructive advice on making this work would be appreciated.