Selling your soul in order to save your life from a revenge seeking dragon mama would be considered the wrong reason for a lot of non-evil characters... at least thats what Elan would say, and since we are talking about V the RIGHT reason to sell his soul would be in order to acquire new heights of magical prowess that his years of study and complete lack of trancing couldnt achieve on its own.I don't know that "I accept your offer" to the imp would work - remember, it has to be the right 4 words to the right being at the right time for the wrong reasons. To me that seems to imply that there would be a right reason to say those words to an imp, which I find hard to believe (for a non-evil character).