So I´m playing my BBEG game tonight, and I´m planning on using Wail of the Banshee tonight. I feel like 200 damage is on the low side for a level-9 spell, but I also DEFINITELY don't want to hear that I hit them with 600-800 damage in one round illegally afterwards.
10 per level to every creature affected, with a number of creatures affected equal to your level.
In 3.x, this spell was 'save or die'. In Pathfinder, like pretty much all other insta-kill spells (with the exception of Phantasmal Killer and Weird), it has been toned down to a measly 'save or take some damage' effect, which, in the light of PF's hit point inflation, makes it pretty sub-par for a level 9.