A good character arc is handled with the same deference as nitroglycerine. On paper it’s a simple combination of basic ingredients but in a writer’s unsteady hand they can destroy everything around them. Hopefully you have a plan or sufficient experience to execute a character arc combined with a great deal of effort to craft solid supportive piece for your story. But what no writer wants to hear after that is, “Fantastic. Do it all over again.” It’s dreadful in the same manner as starting a story anew after completing one you’ve spent several months with, charting out with no sense of direction or familiarity. Yet, in a multipart or long-form series there’s no real means of avoiding it.
In conventional story structures all story threads will align at the climax: The love interest confesses their feelings, the student learns the final lesson their departed teacher passed onto them, rivalries are settled, and character arcs are completed transforming a character from one version of themselves to another. For a conventional, one-off story it works perfectly to fulfil every promise at the highest point of drama. Problem starts when you write part two of the story. Ask yourself, “What now?”
One solution, if you stretch the term, is to not change the character at all. This is common with long running serial works like the James Bond novels where the titular character is a womanizing, hard-drinking, non-committal, gentlemanly secret agent till his last appearance. James Bond is cool and all his stories follow the same formula, but if the formula is done well each time it’s hard to say no. If everything around the central character is interchangeable, no character arc is necessary.
But where this logic falls off is in a non-serialized sequel where everything that happened in the previous adventure still matters going into the next adventure. If I could pause on the still matters line for a millennium I would. No one cares if James Bond picks up a new woman in his next venture because the last was only described for her looks. But if a boy and girl meet and fall in love and get married in part one you can’t be expected to forget about it in part two. If James Bond married his eye candy in each book only for her to divorce him or die between volumes it’d be a completely out of place running joke. You can’t roll back character development and keep the audience invested for once it becomes interchangeable it ceases to affect the story.
The solution is to find the natural outgrowth of the character arc just completed. Find what the difference between the past and present character and think how this’ll effect their life. When the character returns home at the end of their hero’s journey how did they approach their world with their old outlook versus how they’ll approach it with their new one? Do they have a new method of problem solving? What conflict is there between their new way of living and old the world around them?
Say a character finds their faith in God. They should be reexamining their world through that different lens and making the effort to change how they act towards other people. Perhaps rather than fighting their old rival next they meet they speak of forgiveness whilst trying to put themself in the other’s shoes and eventually pitching their religion to them. Besides how they act, the new character arc could be a challenge to their faith (perhaps instrumented by their rival) which will reveal the limits of what they can put upon their deity and what they have to take personal responsibility for, including their ill-actions in the first book. Some might claim this pigeonholes the character to forever be defined by the status of their faith but I contend there’s more to work with there than having them flit with the faith for the entire series. Past that, the character can evolve past their faith, losing it and, rather than reverting to their place in the first arc, developing an internal sense of morals justified by the innate sense of good in all people instilled at birth. Be a pretty good character arc to use in a lonesome wanderer volume.
If you have the energy to string new arc after new arc together over many volumes you’ll end up with a well-rounded character—a complete sphere. Much like real people these characters can become someone unrecognizable between one point in their lives and another. Biographies provide an in-depth examination of how a person can change over time especially those who lived through places and times of great change which forced them to confront new difficulties. Study history and find the step by step logical and philosophical justifications which lead peaceful, isolationist nations to have a populous clamoring for war and then back to peaceful isolation and then onto colonial ambitions. Apply that slow change unto an individual as if they lived for hundreds of years during those events. For an expedited but still valuable take at this listen to a musician’s catalog and see how interests and viewpoints and how those’re discussed change over the course of the artist’s career. Singer-songwriter is a good genre for this end with its focus on personal lyrics and the longevity of many of its artists.
Don’t be frustrated if at the final page the character circles back to where they began. If it takes forty years to start at one point, move in the complete opposite direction, and then come right back around to where you started, thinking the same way about the world and doing the same things you were doing in your youth, it’s not a waste. You found where the river ends and where the ocean flows. Back home was and is a treasured thing. Everything it took to leave and return is wisdom. Call it a hero’s journey with five or ten or fifteen imbedded journeys within the grand circle. People change, it happens every day. Keep your mind on it and you might find yourself going through a whole arc in a single day.