LOL, he's not going to be that major a character, and I hadn't thought of him so much in the lusting terms, more along the lines that he would be a) a Pure-Blood Snob and b) the sort who would see "dark arts" at work everywhere. He would be one of those discussed in Book 4, who is so intent on wiping out the "dark side" that his tactics become as ruthless as those of the evil Wizards he's fighting. He's also doubtless very "anti-Werewolf." Seriously, I don't think he'll get a lot of page time, but I needed a head for Slytherin.
Plus, Dumbledore's not in charge for the first couple of years my main characters are at school; he's the Transfiguration teacher and head of Gryffindor.