There could be several reasons why the author chose to write this story crossover. One possibility is that they wanted to explore and bring together two different fictional worlds or characters that fans of both would enjoy. They may have also wanted to challenge themselves by integrating various elements and lore from multiple sources into a cohesive narrative. Additionally, writing a crossover could be a way for the author to pay homage to or show appreciation for the original works that inspired them. Ultimately, the author likely wrote the crossover to entertain and engage readers who are fans of both of the franchises involved.
