Daddy
Apart from some apparent holes in authors knowledge about human biology... I just realized that all his skill upgrades and stats are just there for show. There doesn't seem to be any limitations to his magic even if his corresponding skill level is low. With zero in wandless magic he could easily manipulate a chair, then transfigure it (might have had 10/100 at the moment of transfiguration). With as low as his combat magic was, he simply exploded few death Eaters effortlessly. But what I see as a most useless of his skills are his social skills in general and seduction in particular. Ha charms everything that walk the earth just by existing. His skill in seduction is a useless as the "g" in Lasagna.