George Darrow was a man who sold his soul for fame.
George Darrow made a deal with a crossroads demon in 1996. He wanted to be famous, but it did not turn out the way he wanted; he became an incredibly talented artist, but was unable to sell any of his art. So after 10 years, he tried to hold off the hellhound to finish his last painting, using Goofer dust which his grandmother had taught him about.
He did not want Sam and Dean to help save him from the hellhound as he was responsible for all the other deals the demon made, thus believing he deserved to be dammed.