User blog comment:IamJakuhoRaikoben/Chapter 415: And It Shall Become Your Will To Live, Review./@comment-24102956-20150112215027/@comment-4829046-20150113065306

The Demon Clan would wipe the floor with Tartarus and they haven't even regained all of their power yet. Tartarus has been repeating the fact that they are at their peak in Etherious form but were still defeated by a considerably small number of opponents while on the other hand, Hendrickson alone, who was still inferior to a True Demon, was able to hold his own against all of the good guys.

Still, we don't know the capabilities of the Demon Clan. If they are weak to say, Keith or Tempesta's powers(because we all know they can somehow manage to negate Marde's trump card), then they are royally screwed. But still, they can react at far greater speeds and might end up destroying the Demon Gates before they even have time to enter Etherious form.