Visit the Badlands!
The Mortdebois family has resided at their estate Malaterre for almost eight hundred years. Nice wizards make sure to keep well out of the place. Muggles in surrounding areas has been taught to avoid it for centuries. Even in our modern times Muggle mothers can be heard warning their children: "Do not stray too far from home or you may end up in the Badlands". According to neighboring muggle folklore Malaterre is a hidden landscape surrounded by fog, steep cliffs and a rather repulsive swamp. In the middle of it lurks an old ruin of a medieval castle. However, the place seems to be completely eradicated from modern maps, as if it had never actually existed, an old superstitious legend.
The Mortdebois family likes to term themselves "Wizarding Nobility". The French Ministry of Magic prefers to call them "a bunch of nasty scoundrels that has made Dark Magic their trademark throughout history".
Meet the Family!
Mortdebois Senior and Lady Pestilentia: The (not overly) proud parents of Mortdebois Junior has never bothered to qualify as Mr and Mrs Congeniality ot the wizarding world.. They spend most of their time brewing unspeakable potions and reading forbidden literature about Dark Arts.
Uncle Guillaume: rather senile nowadays and exiled to shuffle among the cobwebs in his chamber at the Eastern Tower. When the family recieve guests they sometimes feel obliged to let the old Warlock participate at the dinner table, just to keep up appearances. Unfailingly he proves to be an embarrassment at those occasions - trying to eat the candle sticks, feebly conjuring up the Dark Mark by muttering "Morsmordre" and being an old nuisance in general.
Aunt Influenza: She is not as old as Uncle Guillaume but just as crazy. In fact even crazier. Her condition manifests itself in the relatively harmless persuits of screaming like a Banshee and occasionally taking potshots at family members and House Elves with her wand through her bedroom window. Needless to say, it is a fairly good idea to make sure her door is locked from the outside.
Never mind young Mortdebois. Treat him with indifference unless he forgets to mind his manners. Lock him up with the Boggarts in the attic until he learns how to behave. Let him sleep in the Family Crypt until he manages to conduct himself properly. If he stumbles or drops something, just use your wand and send him flying smack into the wall. Give him creative punishments and teach him that there's no use to explain or apologize. Never mind young Mortdebois. Just make sure he keeps out of your way!
No, it is not cruelty. It is the way children has been brought up at Malaterre for generations: breaking them in order to make them strong wizards (just look how splendid the rest of the family has turned out..). It is just for his own good. One day he will be very grateful!