As I may have mentioned previously, my story will be in the fantasy genre.
I have a preference for the genre, and to a lesser extent Science Fiction, due to its lack of anchoring in the present. The current world is a complex place, and to have good drama in a modern-day novel you tend to have to have nasty things happen to people. Being killed to protect long-held secrets, serial murderers, and moving to prevent all-out war.
While fantasy novels can (and do) contain such things, that it is not in your current world provides a barrier to being truly disturbed by what the authors come up with in the actions of their antagonists.
The initial aim for my story was from the ‘Keep It Simple Stupid’ model. Establish your overall storyline, do a bit of research, put a few more key events between the beginning and end of the overall storyline, then work your characters into the world you’ve created.
All was going well to begin with. Main antagonist needs to get from Point A to Point B to claim the power to rule.
Then the aim went from ruling the country to ruling the story world.
Then characters from other parts of the expanded world became a ‘main antagonist’.
Then ‘balance’ was required by creating main protagonists.
Then research showed me the world I was building was more complex than the KISS principle seems able to allow.
So, the seven locales (one for each book) to get from Point A to Point B has expanded slightly. There are now nine countries (and provinces for some), seven main antagonists, seven main protagonists, and nineteen (and counting) supporting characters.
Well, it will definitely be epic fiction. Let’s just hope the end product is enjoyable epic fiction.