In my outline, my main character finds out my supporting character has been manipulating her from the beginning and wants answers. Initially, I was going to write a flashback chapter to explain how that came about, but I’ve read readers and writers hate flashbacks. The flashback was going to be his explanation. How else could I achieve this?
Just as there are anti-prologuers, there are anti-flashbackers. Don’t let them dictate your storytelling choices. I hate the thought of writers avoiding devices that’re right for their stories because they fear knee-jerk rejection of the device itself. What bears consideration is what causes anti-flashbackism: Sometimes flashbacks slam the brakes on a story’s forward momentum because they throw us backward. Sometimes they feel too pat. Now consider that in real life, demanding answers from one’s nemesis requires a present-day showdown, with accusations, denials, miscommunications, and missed opportunities for clarity, recompense, and reconciliation. Juicy stuff! Why not experiment with such a scene? Even if it feels scary to write, stay with the experiment since those feelings could be a sign you’re avoiding “pat” and writing something rich, cathartic, and thoroughly satisfying.