I'm reading through this adventure, and I'm scratching my head at teh statblocks.
The Behir's statblock doesn't make much sense, at least it's Lightning Breath power. A close burst 1 breath, then another close burst one? I know 'exception based design', but the thing just reads awful.
Then the Windstriders. What's the point of the Searching Wind/Lethal Wind thing? The Lethal wind is identical to monster's basic attack, except that it uses d8 instead of d6. Not... all that great, when it's a lurker. The ability to avoid OAs is nice, tho.
The Ice Gargoyles are intriguing, although a little clunky.
Chillreaver is badass. The Seed of Winter, however, is very interesting indeed. I may have to use this for Feywild stuff. Mmmyess.