I had a nephew out on a mission who really liked Batman, and a niece who was preparing for a mission who was a huge MCU fan. Every Fast Sunday I would send them a letter (between 3000-4000 words each) teaching a lesson about missionary work from a specific superhero. The ideas actually originated from when I was an early morning seminary teacher and I would regularly make superhero references in my lessons to keep things interesting. After 17 letters (9 from Marvel and 8 from DC), my family encouraged me to put them into a book and publish it on Amazon in case there are other superhero nerds like us that could benefit from them. So I wrote one last chapter about the Savior (the only real superhero to ever exist), and put it out there. Its not for everyone, but those that have super-ears to hear, let them hear.
https://www.amazon.com/dp/B0CGTWTMT6/ref=nosim?tag=cougarboard07-20