Reminds me of an old movie I saw long, long, LONG ago, about a beautiful woman who never aged. She had a ring with which she would stab a young man in the neck as she kissed him, that would extract his essence and leave him shriveled and dead. She would then create a potion with it that would restore her youth and beauty, but after a while she would need to seduce a new victim. Great old b-movie, wish I knew the name of it.