We understand that many players want to fight against strong monsters such as Fafnir or Behemoth and wish to obtain special items. However, we don’t think that a lower difficulty will result in the reduction of game play stress.
It is not difficult to move NMs or HNMs to the battlefield, but it would destroy the uniqueness of each monster. We believe that because these powerful monsters dwell deep inside dungeons, players fear them more and the dropped items resulting from defeat of said monsters have added value because they are difficult to obtain.