Thus Spake Zaraborgstrom/MutationCannotBeEscaped

Mutations Cannot Be Escaped

Can a raksha who has an Assumption Charm for a mutation shape his body away? Is there a textual example of this?

There is an explicit example of a raksha dropping a body not purchased as a mutation. That may be what you're thinking of, particularly if you missed the word "not". It's in the generic text for Assumption-type Charms.

On the other aspect of the debate:

If you've mutated yourself a shape, you're stuck with it. You have a shape and there is element stuff in it, just like if you refuse to turn off the Charm when you reenter the Wyld.

You can think of mutations as a kind of Tell. It's a pretty blatant Tell, for Assumption Charms. But it's still just a Tell. You can do whatever you like, shaping-wise, except actually denying that you have that shape and that element. If you want to be a mouse, be a mouse, but you're still shaped like, I dunno, a woman made of fire or whatever. If you want to keep your shaped body in a tomb somewhere, or hidden in a mecha, that's fine.

If you want to be a gigantic crocodile and keep your real shape in your pocket; if you want to be an immaterial ghost of yourself; if you want to be a hundred million flowers each shaped like a little you; if you want to be "a woman made of fire, that is not here" -- those are stunts.

If you want to stop being a woman made of fire, too bad---it's like having a fur pox and wanting to not have fur, or a tail Tell and not wanting to have a tail.

Summary

The least intrusive interpretation of what I've just said: yes, other raksha know that you have shape. Yes, if a Creation-born is looking at you, they can defy the shaping and realize, "Why, this isn't a mirror—this is a woman made out of fire!" Otherwise, it doesn't constrain your shaping at all.

The most intrusive interpretation: sorry, but you voluntarily took on shape. You voluntarily decided to be "five Graces, plus a shape and element." Your Heart shows a person with a shape and element. It's only a one-point mutation, but you know that point in the invasion storyline where the princes of chaos realize that they can't go back unless they win? I think of that as just one point of mutation. Banality sucks, even though the Banality of the Age of Sorrows is a lot like the Terror and Adventure of later eras.

(The difference between these interpretations: pretty much, how far you can ignore the fact of having a shape without a stunt.)