A horrific device only employed by the most black hearted of magic users.
A horrible torture device. Not for the squeamish.
There are a lot of bad people out there. That is why we must torture you: to keep you safe.
Many and varied are the ways of extracting a confession or ending a criminal’s life, and the one usually follows the other.
Magic is a blessing and curse, life and death, birth and undoing, a goal and a way.
Perhaps those that practice elemental magic begin to take on characteristics associated with their chosen element. For instance, an earth elementalist might be prone to agoraphobia, while air and possibly fire elementalists might have problems with claustrophobia. Water elementalists might always seek the path of least resistance. A fire elementalist might have a cat's opinion of water. This could also apply to physical differences. Fire elementalists might have a freakishly high metabolism and a permanently high body temperature. Water elementalists would probably never get dehydrated, but might slow down a lot when it's cold. Etc, etc.