Sefariel grunted in acknowledgement at the glitterdust spell; it had been what he had had in mind. Unable to lend much to the offense, and unwilling to break his own invisibility (brief though it would be), he reached out and tapped Aron on the shoulder with an invisible hand as he incanted a few words. Suddenly, he wasn't quite there... well, he was there, but where there was seemed to shift by the moment.
Spoiler: OOCCasting displacement on my bro, for a little extra defense.