“I’ve spent my whole life pretending to be this guy’s brother,” Dominic said. “I’m not even sure I know what ‘healthy’ is.”

That is more than just a little scary. I wasn't sure at all what you meant by your summary of this or how it would work, but it's like the Truman Show in a very dark place. I must admit I'm intrigued.

And your Derren Brown runs rings around the Winchesters fic MUST BE TOLD.