On Supernatural Season 9 Episode 21, Cas captured one of Metatron's angels, finding himself marked for assassination! Remember when Cas & Crowley weren't DEAD???
On Supernatural Season 9 Episode 18, Castiel turns down Metatron. As you can see here, Sam and Dean also capture Gadreel setting a surprising plan into motion.
Some of these characters may be your favorites, but it's not because they're paid the big bucks, it's because when nobody is looking they steal every scene they film. The nerve!
Why do they call this place The Empty? It's full. It's full of sorrow and despair playing over and over again of angels and demons dreaming about their regrets. Forever.