I don't have anything fruitful to add on the nature of the MiTD's darkness feature. I did want to note though that the Barbed Devil that Count Durkula summoned, like most Devils, can see perfectly through magical darkness, even Deeper Darkness. If this really is TE walking through the door, with the LG following right behind the Order, I foresee hilarity (and perhaps some more clues to the MiTD's identity) when the Devil realizes just what s/he's up against. Right before s/he Greater Teleport's away. (Although, with an INT of only 12, would a BD recognize the MiTD? The Circus patrons didn't after all.) Of course, the MiTD's darkness or the umbrella's powers, may trump that supernatural ability, but it's still something to watch for.

Thanks, Grey_wolf_c, for your lengthy commentary on my post. Your efforts to foster discussion on this thread, as well as ride herd on the wilder specualtions, are very much appreciated.