The Darkling (2000)

When mechanic Jeff Obold meets the wealthy and mysterious Bruno Rubin he is exposed for the first time to the finer things in life But Jeff soon discovers the source of Rubins power a caged creature called a Darkling which possesses the power to create incredible wealth for the person who will pledge unending companionship Now as Jeff sinks further and further into the blackness of a soul sold to the devil he will discover there is a high price to pay for the fulfillment of his dreams