In regard to the Imperius, it's possible that an imp's natural "cloaking" prevents potential masters from being able to remember them long enough to make practical use of them. It's also possible that they don't speak human languages. Has it ever been established how Imperius commands are conveyed to targets?
Maybe even a captive imp is too well concealed to Imperius, although if they're that well cloaked it raises the question of how people even know they exist.
In the original canon, Crouch Jr. as Moody was able to Imperius a spider, which implies that it does not require that the recipient have human language capacity, or even be intelligent.
Also, in canon, in book 7 the protagonists themselves use the Imperius themselves (as part of the break-in to Gringotts.) There we get the best look at the actual mechanics of the Imperius, including that we see Imperius commands being issued telepathically as it were, from the caster's thoughts.
This is a new thread to discuss Eliezer Yudkowsky’s Harry Potter and the Methods of Rationality and anything related to it. This thread is intended for discussing chapter 99, 100, and 101. The previous thread is at nearly 500 comments.
There is now a site dedicated to the story at hpmor.com, which is now the place to go to find the authors notes and all sorts of other goodies. AdeleneDawner has kept an archive of Author’s Notes. (This goes up to the notes for chapter 76, and is now not updating. The authors notes from chapter 77 onwards are on hpmor.com.)
The first 5 discussion threads are on the main page under the harry_potter tag. Threads 6 and on (including this one) are in the discussion section using its separate tag system.
Also: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27
Spoiler Warning: this thread is full of spoilers. With few exceptions, spoilers for MOR and canon are fair game to post, without warning or rot13. More specifically: