Cannibalization is one of the most powerful tools a writer can wield. But it’s not a “genuine” tool in the sense of narrative techniques, POV experimentation, word revision, etc. Still, it is a tool all writers should freely use.
So what is cannibalization? Also known as story Frankensteining (I made it up) or if you want to get literary, concept synthesization, is taking used or older stories, characters, and combining them into a new product. Maybe you had an antagonist who ended up being so cool and interesting you decide to scrap the story, take their concept, and then write a whole new story around them. Cannibalization. Maybe your sixteen-year-old epic fantasy didn’t work out at 250 pages in a five act story. Ten years later, you come back, remove what you don’t like, revise, and breath life back into its flatlined body.
Writers have been doing this since forever. Loosely connected short stories are jerry-rigged together into a cohesive novel. An archetype character is slotted into a new novel with a different configuration and role in the story ala Osamu Tezuka’s Star System. In common terminology, this is often what a spiritual successor is in terms of delivery and themes explored.
Not all ideas make it onto the written page. Not all characters get to leave your gray matter noodle. That’s ok. But if you have a passion story, a world you really want to bring to life, along with another one and they have similar tones? Remember, if you’re unpublished, no one cares that your novel is a restitched Lazarusian monstrosity. All that matters is you produced a passion project that sold.
Sometimes, all you need is a few years removed from a work, splice together two worlds, reconfigure characters and relationships, while maintaining the spirit of the original works. Cannibalization is a technique that works. Give it a try, you never know what you might produce.