Oh yeah, and don't bother trying to Invite Archaic Demons, Ultima Demons, or Apandas - it is impossible. Invite also won't work on any story-related NPC, whether enemy or guest.

Boss characters & Demons are also immune to alot of status anomolies. Sleep, Don't Act, Frog, Death, Death Sentence, Confusion, Doubt Faith are generally worthless on bosses. Slow, Blind, Chicken/Foxbird will usually work. (With Foxbird or Chicken, you can reduce Brave to 0, but they will not turn into chickens. Does eliminate their reaction skills though.)

Good luck again.