Maybe it was your unconcsious showing you mercy?
What about instead of a young girl falling in love with Satan, a young girl is possessed by satan, only satan is a woman? Then, because she is essentially Satan, she rises to the upper echelons of influence and power. You could use the Dr. Jekyll and Mr. Hyde cliche instead of the Beauty and the Beast cliche.
Have her being all insane in private and charismatic in public. I'd would read the first 14 pages of that.
To give actual advice: pay attention to ability for story arc and character developement. Where do you go with a forbidden love story that isn't in the one line synopses? You remove the B, C, and all subsequent storylines with such a narrow premise. One that demands all action feed the main storyline. Only so many ways to do Romeo and Juliet.