First I would like to thank everyone for your awesome reviews and since nearly all of you asked:
Yes, I will write a sequel to "House of Madness", which will include years 2 to 7 at Hogwarts in a series of oneshoots (all of them probably shorter than HoM), though it won't be up for a while yet, university keeps me busy.
Said sequel will be titled "House of Madness: Schoolyears", because I'm feeling particular creative today…

Second, I have a little gift for you; here is the story of how Hermiones obsession with finding a purple bunny named Merlin started. Enjoy!

Merlin the purple bunny

Our story begins when Hermione is five years old.
It's the last summer before she'll start school and the seventh wedding anniversary of Doctors Helen and Richard Granger, who had been gifted with a weekend in Paris, all expenses paid by Loki, who was currently on babysitting duty too.
Said Trickster was amusing himself by tripping snobby tourists in Scotland's moors, while keeping an invisible eye on his charge.
So no, he was not being irresponsible and what would happen this day was not his fault!
(It totally was. He caused it.)

Hermione was wandering along the borders of the moor she had asked Loki to show her today, as it had looked really cool on TV yesterday, not really listening to the guide drowning on. She had long since found something, or rather someone, far more interesting.
The man was pretty old (like thirty or forty), not very tall, wearing a pristine black suit and, most importantly, he had two faces!
It was, like there was something else behind his normal, human face, like a storm cloud, twisted and distorted and twitching and from time to time you could see it in his eyes.
It was fascinating.

Crowley, at the moment still right hand man of Lilith, queen of the crossroads, smiled, even though he could feel the mud ruining his shoes.
Even though he was kept busy with small fry while something big was starting to take form.
Even though he was back home.
After this last, stupid tour, the frustrated guide would be ready to take the deal, a soul more for his collection.
Maybe he could even bag one more deal here, today… Potential clients were everywhere, you just had to look.
Like that bickering old couple, long since past loving teasing and well into a cruel war…
Like that sick young man, cancer, depression, only a few more years to live and that was only if he didn't commit suicide before…
Like that lone little girl, power flowing through her, but no friends, parents nowhere to be seen…
Like that… The little girl was staring at him, apparently utterly fascinated.
Well, he could probably work with that, if he could bag that powerful, innocent soul for himself…
And no, Crowley did not have a bad feeling about this slip of a girl.
(He had. But that could just as well have been the invisible archangel…)

The double-faced man was coming over, maybe he'd tell her what he was if she asked really nicely?
Hermione grinned.
"What are you, please? I know that you are not human! Why do you have two faces? How…"
The man froze for a second, then he drawled: "My, my, aren't you a precious little one. I am the king of the crossroads, darling, I can make your greatest wish come true. Aren't you lucky you met me today?"
"Hmm… My family already gives me everything I want. And you don't look like a king."
"Why you…" Ops, it seemed she had angered him.
"What else would I look like, brat?"
Hermione cocked her head, thinking really hard.
"Like a bunny! With flappy ears and twitching nose and fluffy, purple fur!"
(Like Fenrir's lunch.)
The man's second face clouded too, he took a threatening step towards Hermione.
"Trying to insult me?! Stupid brat, don't you know…"
Another step, Hermione squeaked, jumped back. Now the man wasn't so fascinating anymore, he was scary! Like a monster and she really wanted him to be a bunny again! Now!
The double-faced monster took another step and her magic reacted.

Unfortunately, a child's accidental magic, unlike what adult witches and wizards could do, often acted in strange, unpredictable ways.
The stronger the child, the more emotionally upset he or she was, the crazier the results tended to be.
Mix in a demon and an archangel-trickster…

Too Hermione, first there was a double-faced man, who somehow reminded her of a bunny, then he turned into a decidedly unbunny like, scary monster, then there was a rush inside her and he shrunk down and he was a fluffy bunny, just like she had imagined, with twitchy nose and purple fur.
Hermione squealed and kneeled down to scoop up the bunny and enthusiastically cuddle it to her chest.
"I will name you Merlin. Merlin, my purple bunny!"

Too Crowley, he was just moments away from teaching the impertinent brat a lesson (and possibly dispose of her body in the moor), when he felt her inherent magic wash over him.
He shrugged it off, just a bit of accidental magic, child play for a powerful demon, when it suddenly, impossibly took hold of him!
What was happening, how could that little girl, born witch or no, have this kind of power?
Crowley was panicking; he could feel his meat suit shrink, change.
He tried smoking out, using his powers, any of them, useless!
Flee; he had to flee, now!
Newly bunnyfied Crowley wiggled out of the girls iron cuddle and hopped into the moor.

A few steps away, the real culprit was doubled over with laughter.
That would teach that stinking demon not to mess with harmless looking little girls and certainly not with his goddaughter!
If he survived the moor for a week, that is.