I'm wondering: Do you think Serini's orange-voiced companion could be another member of MITD's species? She's said that she "belongs with the monsters" so it would seem more likely that Orange Voice is a "monster" than that it is a member of one of the civilized races, it would set up the reveal quite nicely, and it would be appropriate to the gag to have another member of MITD's species show up on-panel... while invisible.