On the other, there was no guarantee she would remain on their side of the battle: he and his master had briefly touched on her motivations during their pre-invasion discussion, and he had noted that it would be incredibly easy for her to be swayed to the cause of the Equestrians, especially if her restoration failed. As it had indeed failed, there was nothing beyond the master himself to keep her on their side, and the forces of good had an aggravating tendency to take full advantage of this type of weakness.