Okay so hear me out. Demon slayer x Httyd crossover with a female Hiccup, she runs away from Berk after getting yelled at by stoik when she's 8. Cool, right? OK, so femHiccup runs off but along the way she gets snatched up by some human traffickers because she very much so resembles her mother Valka who mind you is like extremely pretty, anyway; they travel the whole 5400 miles to Japan. Don't know why yet so bear with me, I'm thinking it's because of the dragons. Now when they get there, Hicca (femHiccup) succeeds in escaping her kidnappers and flees in the direction of the mountain that the Kamado family lives, along the way she encounters several Demons, ( will not be disclosing who as of yet) she gets half way up,the mountain before she finally collapses sue to hypothermia and malnutrition as well as severe dehydration. Tanjuro Kamado, Tanjiro's dad, finds her on his way back from selling charcoal and immediately takes her in. The Kamado family nurse her back to health and take her in, teaching her how ro speak Japanese and their traditions, but because of the near death experience it wakes an ancient magic that layer dormant for centuries. Thankfully however due to the fact that she was Gothi's apprentice before she ran, Hicca understands some of how to control this power. Hicca has a vision that Tanjuro gets sick and uses her weaving and crafting skills to earn enough money to afford medicine to heal her adopted father. Dun Dun Dun Tanjuro lives.
Now I have more ideas, but I don't want to spoil everything too soon. Of course I literally suck at the writing part of the process, so if anyone who is actually able to write could dm me on here that would be great. I've had this idea in my head since I got into demon slayer and I think it would be a great crossover.