AUTHOR'S NOTE — growing up I was a big fan of the Harry Potter series, however I am not really an HP-fan anymore. Regardless, there have been tons of rants from Harry Potter fans about how Albus Dumbledore should not have left the titular character on a doorstep (however they always get it wrong when they saw it was mid-Winter when it was actually mid-Autumn). Well, being a major fan of the Kimetsu no Yaiba series, this is my take on why this was a mistake.
November 1, 1981
Surrey, England
Left on the doorstep on a certain home in Little Whinging was a one-year-old wrapped warmly in a blanket with a letter-filled-envelope tucked next to the child. Supposedly this child was meant to be important to a certain group of people, but tonight this unfortunate boy would be food.
While the demons in Japan had been functionally wiped-out by mid-December 1915, there were some who had occasionally left the country beforehand. One such demon was taking a walk late at night when it came across this tasty little morsel. Grinning hungrily, it walked over to the boy.
"Well, well, well, aren't I lucky," the demon chuckled to itself as it sat down, slicing the blanket open with a claw-like fingernail before picking up the baby, who began to stir. The letter that had been tucked next to the baby fell to the ground, however the letter didn't matter to the demon.
The few demons who had been able to make it to Europe found it very easy to settle, especially with crazy humans running around wielding sticks who could supposedly use magic. The idiots.
These dumb so-called "magic-users" were useless against demons, but they sure were tasty.
As the demon chomped down on the one-year-old, causing it to wake up and scream. Wanting to remain unnoticed, the demon quickly ripped off its head and ate that too. It continued to eat until there the one-year-old was no more. It tasted good, but the demon was still hungry.
The demon stood up and turned around, smelling more humans within. Grinning, the demon kicked the door in before entering. It could sense its prey upstairs, and so up it went, going into a bedroom where three humans slept — two adults on a bed and a baby in a crib next to the bed.
It went over to the large beefy man first, slashing his throat and then reaching to slash the throat of the woman as well. With them dead, the demon then went over to the crib and picked up the chubby-baby who it ripped apart as it gobbled the child down. Then, the demon ate the parents.
November 8, 1991
Surrey, England
Two cloaked figures stood before the house where the demon had fed. Over the course of the several days following, the demon had fed upon other nearby-residents and the news picked up the story as a cannibalistic-serial killer. If only those foolish, ignorant humans knew the truth.
"It appears we are all doomed," the eldest of the three figures said as they looked at the house.
On the doorstep of this house the blanket and letter were found, covered in blood...
...as were the remains of the occupants within.
"But...what could have happened...a werewolf," the other figure, a woman, asked.
"Perhaps, however there was no full-moon," the older figure replied.
"I knew we shouldn't have left the boy here," the woman said. "I told you so."
"Yes, that you did," the older figure sighed sadly.
And this, is why you never leave a human unattended. Ever!