The series I'm writing is a horror comedy, where the first book follows a satanist trying to sacrifice the protagonists to The Devil. In the second book, the protagonists confront The Devil face to face, and kill him. I have a wonderful idea for character drama and arcs I would like to explore in the third book, but I'm facing an obstacle in terms of the external conflict of the book, which is the fact The Devil is dead. I'm considering that maybe the antagonists of the third book could be a cult who wants to carry out The Devil's mission, but I'm wondering if I'm missing a better idea. Thoughts?
Kinda vague, you don't mention much about your story so I'm just going to toss out a few options here (and a question or two).
Are you using the version of the devil where they have many names (Asmodeus, Azazel, Beezlebub, etc...) or the version where all those other names are separate demons?
Second, Does the threat have to be Hell-based (satanists, demons, whatnot)?
And third, do your heroes have any sort of powers (magic, power of faith, resident angel in their head)?
Depending on how your world is built you could have:
An ambitious demon underling looking to fill the devil's job.
An angel looking to punish the mortals for meddling in things above their station.
A fallen angel (who acts righteous but isn't) just looking to cause trouble.
A shady government organization looking to "recruit" the people who brought down the devil.
The devil, he wasn't really dead, after all, how do you really kill an immortal being?
The devil's kid, raised by the cult and out to avenge daddy.
Some other religion's devil or god out to secure territory in the hells.
Like Teak answered - your question is pretty vague.
But I will try to answer it:
You don't need a bad guy for external conflict.
If the devil is the antagonist in books 1 and 2 but dies before 3, you can have your protagonists try to fix his bad deeds in the 3rd book.
Basically, the protagonists would have to travel around the world, freeing the devil's prisoners, defeating his remaining minions, covering up his footsteps so no one else will follow them, and an interesting idea would be to have the protagonist's reform society into a more just place where evil can not run rampant. This would turn your 3rd's book conflict from devil vs people to people vs society.
Or, if you are committed to a bad guy, here are some options:
- One of the devil's followers bring the devil back to life
- One of the devil's followers takes up the role of the devil
- One of the protagonists betrays the others and sides with the devil's followers
- One of the devil's family member or friend, seeking revenge
- Devils from other worlds and religions form a team to defeat the protagonists
- The devil still controls people from the underworld
And if none of these ideas work for you - just insert the 3rd book after the 1st and before the 2nd so the devil is still alive.