Ciel had been feeling off for many days now. His nose was almost always stuffed, his eyes watered constantly and it had become the norm for him to sneeze without any immediate reason. He hadn't caught a cold, for he had no fever and felt no chills, and he was not reacting to any sort of allergy as there were no cats near.
It was quite peculiar to say the least.
Sebastian, of course, was spending hour upon hour researching the boy's symptoms, old home remedies, and possible family medical issues from the vast library that inhabited the Phantomhive manor, for a sick soul was tasteless compared to the richness of a vengeful one. But despite his laboured searching he found not a sign or idea that could aid or explain the illness that the Earl was enduring.
Day after day the sickness ran on, to a point the boy was bedridden, yet one day he felt completely better. His symptoms kept up, of course, but he had the energy to venture outside into the home's luscious gardens.
The butler held back, making tea for his young master, leaving Ciel to walk the rows of roses by himself. It was a calming feeling, a sense of relief to surround himself by the scent of the flower he loved so much.
This was the point the boy noticed something odd, for his legs and arms had begun to grow thick, black hair. At first, Ciel felt a little pride in his growing into manhood, until he realized the hair refused to stop. In only minutes his arms, legs, stomach and chest had been hidden by the thick, course fur-like hair.
Confused and afraid, the boy called out for his butler, unaware of his ever changing appearance upon his face. His body began to shrink, a set of ears popping from a top his head, a tail growing from his back and his whole beginning transformed into a slick, tiny, black kitten.
Of course. His eyepatch remained but beyond that he had turned into a cute, fluffy black kitten with ocean blue eyes and a long tail that swung throughout the evening.
The boy once again tried to call out for Sebastian, his eyes scanning his surroundings from his new perspective, but all that came out was a high-pitched "meow".
At this point, the boy realized the difference in his paws, in his movement, and in the feeling of a tail wagging behind him. Everything came into realization at once.
He had been turned into a kitten.
And he was allergic to himself.
...
Sebastian became uneasy after many hours without his young master ordering him around.
The tea he had prepared had grown cold, as did the dinner and the dessert he had ready for his master's return, and this idea bothered the demon so.
It was only when the sun began to set that the butler decided to gather with the servants and begin patrolling the area in search for the young Earl, which embarrassed the proper butler deeply. The servants, of course, were eager to help and quickly began tarring up the home and garden in search of the missing boy. Yet, not a sign of the boy could be found, and Sebastian failed to even be able to sense his presence in the garden at all.
He was beginning to lose his mellow facade, an emotion that perhaps could be explained by fear crossing the demon's face. Of course, it diminished at the sight of a kitten with an eyepatch running up to him eagerly.
It clawed at his pant legs and shoes for attention, something Sebastian would undoubtedly give. His hands were warm, as they always were, and as he held the soft kitten in his grasp the warmest of smiles grew on his face.
"You should be here, you cute kitten. My Master will scowl at me if I allow you to continue roaming his property."
The kitten look unamused, and suddenly sneezed, an adorable little sound the demon had trouble ignoring.
"You remind me of my Master, you know? Perhaps I could persuade him into allowing you to stay here using the idea of your similarities." Sebastian pet the kitten's head, and in return, was bitten on the hand. "Well aren't you a playful fellow?"
Annoyed with the whole charade, the kitten jumped from the demon's arms, pawing at the ground in front of him as if trying to write. To the kitten, the spelling clearly read "Sebastian, it is me, Ciel!" but to the demon it looked more like an abstract painting of a tree.
"You're quite the artist," Sebastian knelt down, continuing to pet the cat, "maybe I can convince the young Master into making a new you to look like you! Wouldn't that be splendid?"
The kitten looked up at him, appearing to shake his head.
"It's an honour to become a Fantom Co. toy. I think you would be the best candidate. Come now," the butler picked up the kitten, carrying him to his bed chambers, "let's get you cleaned up and fed."
...
Sebastian's room was like that of any servants. It housed a bed he never used, a desk he never wrote on, a few changes of clothes, and a wardrobe to be used for more delicate clothing. He set the kitten down, opening a desk drawer and opening a can of cat food.
Suddenly, bursting out of the wardrobe came a dozen cats, all black and well groomed, running to their master for an afternoon snack.
Overjoyed by their appearance, Sebastian fell back, laughing as the kittens tackled him in a fluffy cuddle. To the demon they were beautiful and mysterious, but to Ciel they were spawns of Satan that existed souly to ruin his day.
Unamused with the turn of events, the kitten began to meow over and over, like an unpracticed middle school choir. It was obnoxiously loud and repetitive, easily grabbing the attention of Sebastian from the other's.
The kitten with the eyepatch stared him down, a look that could kill if it weren't for Sebastian being...well a demon. It reached it's paw up, dragging down it's eyepatch to reveal the contract symbol he had scared across his eye.
"My...Lord?" The butler questioned before hurriedly shoving the kittens back into his spacious wardrobe. "Young Master, how is it you turned into a cat!"
Ciel stared at the man blankly, thinking of all the things he wished to say but couldn't in his current state.
"We must fix this at once!"
...
It took many hours of searching but with the assistance of the Undertaker, Sebastian was able to find a counter-spell to bring his young master back into his human form. It was heartbreaking to say the least, watching the adorable black kitten grow and form back into Earl Ciel Alexander Phantomhive once more.
No longer could he pet his Master, or let him roam freely without worrying about him being kidnapped. And no longer could he leave out food instead of cook, and pour milk instead of make tea. Everyone had changed so quickly back to normal, and the worst part?
Ciel made Sebastian throw out his wardrobe and release all of it's inhabitants back into the wilderness.