When Friends Become Enemies and Enemies Become Friends
Setting up character reversals takes a deep knowledge of your characters. You need a deep understanding of weaknesses and masks. For example,
a woman is in control in male-female relationships and then falls in love. The relationship works for a while but he leaves. She becomes devastated and despite her seeming control is unable to function well in the real world living under the shadow of abandonment.
A low-level cheerful employee who always seems to be there when something crucial happens and then disappears uses his innate cunning and outer cheerful demeanor to climb the ladder. He ends up at the top by manipulating everyone on his way up.
Now think how your story would expand if both supporting characters were in your story. Will your protagonist see the manipulation of the employee? Will she triumph over the devastated woman by winning the man of her dreams?
To know about your character, dig into the under layers and past experiences.
A foible that reveals a deep flaw
A traumatizing childhood experience that lies behind motivation
A stated motivation in conflict with deep-seated internal goals
The more you add to your character’s list of inner turbulence, the more tools you have to reveal the reversal. In your story you will start with the appearance and gradually reveal the nature that changes the character’s action.
Once you have given the reader a solid idea of your character, you can hint at the change to come. To make the reversal integral to the story, drop small hints early in Act 2. Use small clues that the reader and your protagonist may overlook—a gesture, a glance, a comment that doesn’t quite fit.
Build on the character’s underlying change so that by the time you are past the midpoint, their base character creates an obstacle for your protagonist.
Take Your Reader on the Ride
As you complicate the characters around the protagonist, you create problems. Obstacles are the meat of challenging your protagonist. Using character reversals challenges your hero to strive for the goal. A novel-length story provides ample space for you to challenge your protagonist with several character reversals.
Give your hero a bumpy ride. Your readers will love the ride.