I was thinking along the lines of this (from Demogorgon's listing in the MM)
Whenever desiring to do so, Demogorgon uses anyone of the following
powers: Cast continual darkness, charm person, create illusion (as an
illusion wand), cause fear (as a wand of that ilk), levitate (as a 16th level
magic-user), detect magic, read magic, read languages, detect invisible
obiects, ESP, dispel magic, clairvoy, use clairaudience, suggest, water
breathe, polymorph self, wall of ice, charm monster, telekinese 7,000 gold
piece weight with each of his two heads (or w ith but one), cast a
feeblemind spell once per day, project an image, use power word stun
once per day, use any symbol once per day, turn sticks to snakes and gate
in other demons, 85% chance of success: 50% chance for a type I-IV, 50%
chance of gating in a type V or VI.