Quote Originally Posted by Anonymoose View Post
The idea of being tempered so hard that your body is twisted into something else (perhaps something nearby or related to the element in question) hasn't really come up anywhere else, has it?
It's SORT OF come up, albiet by counterexample. Loon Gah's mother in the Ash Tribe questline was also overtempered - but the result was not the twisting of her body, but burning out her mind...

Although, to be fair, this might be a different matter. Loon Gah's mother was, if I recall correctly, subject to repeated temperings, not a single massive supertempering.