How unforunate.
Then I'll have to either find something else or fudge it.
Would Celestial Martial arts be too overpowered in worm if it was learnable by mortals?
Look, it's perfectly alright to get inspired by an aspect of Exalted, then throw out everything that stands in the way of the story you want to tell.
Look at my fanfic. The premise is "Taylor as a god from Exalted". Look at how I treated Sanctums.
In Exalted, a Sanctum needs centuries of work to be built up to the level Taylor has in my story. That's fine in-universe because gods really aren't PCs, so the GM can just declare the sanctum to be as fancy as they want and destroying one will have a real impact.
In my story, a god instead has a Sanctum that's appropriate to their station. It needs some work to get it into the shape they want, but that's doable over the course of a weekend or the like. I did it like that because otherwise, I could not have Sanctums as an element to play around with. I couldn't show lavish, spectacular environments, I couldn't use them to describe the nature of the gods in question, I couldn't do anything with them other than use them as hidey-holes.
So, you want a story where people rapidly learn Supernatural Martial Arts?
Then do it.
Don't worry whether it'd take them a decade at best to learn them in Exalted. You aren't writing Exalted, you're writing your story. There is no actual benefit to being cognizant about how it works in Exalted other than being able to honestly state "I know it doesn't work like that, but I changed it for my story".
What you really need to pay attention to are the implications of how it works in your story.
A lot of Supernatural Martial Arts is just "this person can fight, just better". They're faster, hit harder, can take more damage and so on. Most of that isn't really that different from a superpower that just makes you faster, stronger or more durable, except it's wrapped in a lot of esoteric stuff. If you want that esoteric stuff, that's fine.
But there's also things you can't describe as "the same, just better". Things such as Snake Style actually poisoning someone, or White Reaper getting stronger the more foes you slay, or Ebon Shadow Style allowing your body to become shadow to evade an attack, or Crane Style being able to warp peoples mind towards peace, the entirety of Silver-Voived Nightingale Style, Dreaming Pearl Courtesan Style animating ribbons (and of course, good ol Gazelle Carping) and so on.
Well, that's all the stuff you're introducing into your story and setting. Now ask yourself:
How much will change based on how quickly people can learn it?
How you do that has a huge impact, obviously. Think about that, and now how it fits with the rules written in the Exalted rulebooks, or even how it works in Exalted Creation. Because again - you're not writing a story set there, are you?
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