I'm a librarian who loves anime, manga, and reading a wide variety of genres.
This part gets me every time.
There really isn't that much difference between Seivarden, awakened after a thousand years, and a person awakened after a thousand years to become an ancillary - just that one was killed when they woke up, and the other wasn't.
Also, I love Lieutenant Awn, both for paying enough attention to One Esk to realize that something was wrong and for comforting the new segment (and maybe also the person about to become a new segment?).