Chaos Space Marines are some of the most iconic and dangerous enemies in the 40k universe, but their power level makes them difficult to include in Dark Heresy games. However, I think it can be done. I hope to use an Alpha Legion marine as the leader of a powerful, well-armed cult. I'd be using Black Crusade to make an appropriate character, possibly granting him some Gifts of the Gods.
Have any of you ever used Chaos Marines as villains in your DH games? If so, how did the players eventually defeat them? Since he's intended to be a major villain, I want the encounter to be memorable. I can think of a couple possible ways to build a CSM-centric encounter that doesn't involve the PCs getting slaughtered:
-- Give them significant NPC backup in the final confrontation. IMO this is the least satisfying option, since the players may feel cheated of their victory if they needed help from a Storm Trooper squad to take down the CSM.
-- Set the encounter in a manufactorum, reactor room or some other area with lots of potential hiding spots and booby traps. This lets the players outsmart the CSM rather than outfight him, wearing him down with jets of superheated coolant fluid and falling pipes before knocking him into a vat of molten metal.
-- Have a fairly straightforward encounter with the CSM and his minions, except the CSM instructs his allies to take the PCs alive. If done right this might actually be scarier than a lethal firefight; no PC wants to be knocked out and interrogated by a Chaos Marine