Hello everyone! I'm a first time gm running a black crusade group at my fraternity and I've got a good group of guys hooked on the 40k universe. The problem is I'm starting to run out of ideas for where to go next with my campaign. The group is 3 humans and two space marines (2 psykers, apostate, chosen, and forsaken). It's fairly early in the campaign, and I had them on an imperial world trying to escape, and destroy a rival group that culminated in discovering a violent gang was being backed by a Word Bearer who summoned, via sacrifice, several bloodletters to destroy the PC's. The PC's one with a couple casualtys and are now heading to a deep space space station on the edge of the screaming vortex. They eventually want to organize a Black Crusade so the Vortex is where I want them to go. I guess what I'm asking after a little bit of rambling is what would be some good little adventures in the Vortex that would eventually lead them to power.
Ideas that I have so far.
Fall under the patronage of someone in the vortex.
Do missions such as removing rivals/secretly gathering power/discovering arcane lore.
Come upon a ritual/tech that could turn a young adolescent into a marine (physically at least) and wrest it from those that control it.
Recurring villains from each character's origin story.
I'd like some extra ideas as I'm not the most creative individual.
Many thanks for those that respond!