The higher level the ally, the better the instructor. Magic words must be sent via email, but they may be sent to yourself. There's no level limit for an ally to become an instructor, but instructors can only train allies up to the level they once were. To release an ally, you must go to Menu > Allies > Dismiss, and choose the ally you wish to make an instructor (note that allies in your party cannot be dismissed until they are removed from you party). Magic words are obtained by dismissing an ally, making them an instructor, going to the list of instructors, clicking one, and choosing to 'share'. You can have a max total of 30 instructors at once. For an instructor to appear in your game, you must first either release an ally, or enter in a 'magic word', by going to Menu > Allies > Instructors, and then clicking a blank slot. Once you get 15 allies, you can unlock the school, which is required to use instructors.
