After selling their souls to a devil the name of Black, tall-tale legends Pecos Bill and Slue-foot Sue must elude a hell bound fate as well as every cowboy trying to sell ?em out to that varmint.

The logline doesn't have an inciting incident; that is, the triggering event that explains why the devil is in hot, hot pursuit.

http://en.wikipedia.org/wiki/Pecos_Bill they are Tall tale legends from Texas, nearly as famous as Paul Bunyan but I get your point about the emotional investment.

I've never heard of these characters. The name recognition has not worked, and you've wasted words that could have been used to entice me to become emotionally invested in your story of flawed characters.