I need a sonic-themed monster for a little mini-game I'm Dming. These guys are level 13 and going through a monestary cursed with silence. When they break the silence, I'd like the heretofor entrapped sonic monster to appear and kick their...um..butts. The Destrachan seems a bit weak (even when advanced) and a Banshee's a bit too hard. And if it could somehow make sense that it was trapped in an old monestary, well so much the better.
Any ideas?
Any ideas?