The glowing around the destruction caused by Shar worshippers.
The bangs or the eyes sure may just be coincidence, all three though? You'd have to have flunked selune cleric school to not realize something is up with Shadow
I'm still personally holding out for Shadowheart being a Dark Moon heretic and not a true Sharran, as that might explain why she remains so incredibly secretive even after you "discover" her allegiances.
