I actually like the M!
As for the Garg. idea. I like the idea of "Dramatic" one. I like the idea because they are mythical creatures, very dark and Magical in their own right. I don't think we should go for a BLACK or DARK deck. Maybe a gray or (if you have the white arcane's from E) that spotted gray kind of feel.
I think they would be a nice twist insted of "Angels" and "Demons." It's not an imp either. It's meaner, more gritty, more commonly weird.
OOOOH, the more I talk about it...the more cool it comes to me.
Maybe a smokey "Rock" feeling.
Hmmm.
-Jacob
__________________
|