Welcome to the group. Hopefully we can set you up for success.
You have to be careful with mixing fantasy and fighting, because it is extremely difficult. I'm not saying you can't do it, you can do anything you like, but I would be very careful with writing extravagant fantasy and choreography together unless you intend on using CGI heavily to offset costs.
Look at a youtube channel called Corridor Digital, who do a really good job at mixing those elements into coherent videos. They tend to favor a humorous style, but they know what they are doing with fantasy and fighting.
Another thing is, write for how much money you have. Understand, if you control the development of your full project, you are also limited with what skills and budget YOU personally can get.
If you let another team do the work, they might have more money and assets to use. Really think about how much you are willing to take on if you plan on doing the whole project yourself. Sometimes having full creative control isn't worth it. Especially if this project is just for fun.