Gate of Memoirs/Bewildering Shadow

The Mora the Summoner defeats at the Cape of Sealed Ploys turns out to be another "Shadow." What could she mean by an "obstructive power"? 
Portrait 	Dialogue
Music: "Will"	Music: "Will"
 	
*Mora: This doesn't please me at all... To think I would be defeated by a worthless human...
*Mora: However, I'm but a mere shadow...of the power left behind by the Guile Demon...
*Mora: An obstructive power sealed away...
*Mora: You shall regret this someday...once you realize what a foolish thing you have done...
*Mora: Now yet another seal has begun to break...
*Mora: It is sure to come soon now...the day of your suffering...
*Mora: But knowing that I won't see you suffer firsthand is truly a pity...