Disclaimer: I do not own Kuroshitsuji (Black Butler) or Harry Potter. Harry Potter belongs to JKRowling and her various publishers for the books and WB for the movies. Kuroshitsuji belongs to Yana Toboso for the manga and idea and the studio, A-1 Pictures for the anime. I do not make any money off of this story.

Title: Split
Characters: Ciel Phantomhive, Sebastian Michaelis, Harry Potter, Grell Suttcliff, Undertaker, Hermione Granger, Draco Malfoy, Severus Snape, Albus Dumbledore, Voldemort, and various other characters
Rating: M
Words in Chapter: 1,652
Pairings: None
Warnings: AU, crossover, Older Teen Harry, split personalities, two souls in one body, revenge, demon contract, use of elements from Black Butler two (yet it is otherwise ignored), smarter and more cunning Harry, and whatever else this author thinks up.
Summary: There are times when Fate has different plans for those that are meant to do something more. Nothing will ever stop Fate's plans from happening, even when deals were already made. However, Fate's plan will be fulfilled and the results will be more satisfying than the ones that had already been made.
Notes: This story came to me at random one day. This is a story that goes from the first anime, but borrows only two elements from the second series. Minus those two elements, none of the second series appears, so no Claude or Alois. On another part of the note, this story will only be updated once a month at most.

Spoken dialogue: "…"
Thoughts: '…'
Ciel Speech Physical: "Ciel"
Ciel Speech/Harry Speech when not Physical: 'Ciel/Harry'.
Parseltongue: "Parseltongue"
Articles and Letters: This is a written in story piece

Prologue

A young boy lay on the floor. He struggled against the bonds that bound him. His arms and legs were spread out to form an X. The boy's eyes were a green so vibrant that they looked like gemstones. It was those eyes were darting between two men. One of the men wore a black robe and turned towards a large man with a thick moustache. The large man stood in a corner of the room. Neither man spoke. The man in the robe turned back towards the boy and jerked on one of the ropes. The boy screamed from behind a gag as his leg was roughly yanked. The man then tied the roped to a stake that was piercing through the carpet.

The robed man looked over his shoulder at the large man. "Everything will be done, Mr. Dursley. I will have your boy fixed." The large man's eyes narrowed at the last sentence. The man pulled a hood over his head. Mr. Dursley shifted and turned away from the boy that lay on the floor. To keep from looking at the boy, Dursley focused on some strange writing that was on his walls. The writing was placed between the pictures of a family with two very large men and a horse-faced woman. The boy that was tied to the floor wasn't in a single one of those pictures.

Mr. Dursley cleared his throat. "Are you sure this… Stuff will work?" The man's face paled as he looked at the robed man. The man was drawing symbols onto the carpeted floor. The symbols were in a circle around the boy. The man finished drawing and looked at Mr. Dursley. Dursley shifted as the man watched him in silence.

The man then returned to looking at the boy. "The boy will not be a problem after today. He will either be cured or killed." Mr. Dursley's shoulders straightened. The boy's eyes widened. The man dropped the brush that he had been holding. "Are you that ready for me to do this, Mr. Dursley?" He didn't wait for the man to answer.

The man lifted his hands to the air. He started speaking a language that neither the boy nor Mr. Dursley knew. Purple lights began to appear as the strange words continued to flow from the man's lips. The individual lights then combined into a solid wall of purple that swallowed the boy up. The man stopped speaking. Mr. Dursley looked at him. "Why did you stop? This is what's supposed to happen, right? This sort of freakishness?" The man looked at Mr. Dursley.

He then went back to looking at the light. "No, this isn't meant to happen." Mr. Dursley's eyes widened at that declaration. The light intensified as the two watched something that had been determined a long time ago begin to take place.

Before Present Events: Late 1880's

A man with shoulder length black hair scowled as the body of a small boy slumped over. He looked around as the body quickly cooled. Suddenly, laughter filled the area that he stood in. The man spun around, his armless sleeve flopping next to him. The laughter continued as a person appeared from behind the boy. The man stared at the newcomer.

The person was a female with a voluptuous figure and long black hair. Her eyes were black to the point that they blended in with the bangs that fell into her face. "I would apologize for stealing your meal, but this boy is too important to go to a demon at this time, Sebastian." She began to pet the boy's bluish-black hair.

Sebastian's eyes narrowed. "This contract has been settled. I am owed my end of the deal." The woman laughed yet again. Her hair bounced as she shook her head. Sebastian continued to stare at the woman.

She tilted her head to the side. "I promise that you'll get to see this soul again. You'll even get to keep your current name. However, Ciel Phantomhive is important, Sebastian Michaelis. He is needed in the future. If I were you, I would keep your ears out for a little bird in the future." The woman then disappeared. Sebastian stood and looked at the body of his young master. He then scowled and turned away from the sight. He didn't look back as he disappeared into the darkness.

Present Events: 1989

The young boy groaned as he heard a voice speaking to him. He felt as if he was floating through the air. The words that were being spoken met his ears after another moment. "Do you wish for me to become your weapon? Do you willingly barter your soul for my hand in revenge?" While he heard the words, the exact meaning didn't seem to reach his brain.

The boy groaned as he opened his mouth. "Yes, anything." He then felt a searing pain in his eye. The pain was so intense that he passed out only moments later. However, he could still feel himself floating. It was the continued sensation of floating that caused him to awaken. His eyes opened to the sight of a person kneeling next to him. The boy frowned and sat up. The person that was next to him was a boy with bluish-black hair. The boy's eyes were a deep blue that had stood out from his face.

The blue-eyed boy smirked and stood. He held out his hand to the other. "It is a pleasure to meet you, Harry Potter." The boy, Harry, frowned at the blue-eyed person. He tilted his head to the side. The boy continued to stare at him. "I'm the voice that's always been in the back of your head. You're not insane. I am, in truth, a second soul." Harry blinked yet again.

Harry shook his head after a moment. "If this is true, then why are we only meeting now? Am I dead? Was what I heard not real?" He looked around the area that they were in. The entire space was empty and black. Harry couldn't see a single thing outside of their tiny area.

A strange chuckle echoed in the space. Harry looked back at the boy. The boy smirked. "You're not dead. You have my servant. You are bound to him as I am. He and I never managed to complete our deal." Harry blinked and opened his mouth. The boy held up his hand. "Do not speak at this time. What you need to know is that the man is a demon. You have promised your soul to him in exchange for his help." Harry's eyes widened at that. The boy shook his head. "Yes, I'm certain that you didn't realize it at the time. However, this was necessary. Now, let me introduce myself. I am Earl Ciel Phatomhive. I will also help you." Harry nodded. He then fell over as he felt as like passing out again. Ciel frowned. "It appears as if our time is done for now. I will leave you with a warning before you go. I will be able to take over your body now that I've awakened. I will only do so when necessary. You can also give me permission to do so." Harry didn't get a chance to respond as he passed out again.

He quickly returned to consciousness and found that he was being carried in someone's arms. He opened his eyes and blinked when he saw a man with black hair and pale skin. The man had brownish red eyes that focused on Harry. "I see you're awake, master." Harry frowned as the man carefully set him down.

Harry then bit his lip. "Who are you?" He then felt a nudge against his skull. He blinked as he felt something tell him to pay attention.

He stopped and began to hear something that was definitely not his own voice from inside his head. 'This was my servant. He is the demon that was summoned. He has yet to gain my soul. Now, when he asks what to call him, say Sebastian.' Harry's eyes refocused and saw that the man was now kneeling in front of him.

The man had a hand over his chest. "Master, I do not have a name. It is your job to name me. What is the name that you shall give me?" Harry's mind immediately jumped to the name that Ciel had told him to say.

He cleared his throat. "Sebastian. Your name will be Sebastian." Sebastian looked at Harry when his name was given to him.

Harry's eyes changed. He wasn't aware of the change at first, as Ciel hadn't asked him for control. It just happened. The only sign that Ciel was in control was that Harry's green eyes changed to match Ciel's blue ones. "Do not be shocked by the name, Sebastian. It appears that this is the body that I will be sharing." Sebastian smirked after the words were spoken. Harry's eyes then returned to green moments later. The young boy shook his head. He had been aware of what Ciel had said, though his mind had been a bit jumbled. The feeling of being forced from control had startled him.

Sebastian stood. "It appears as if I have two masters. However, I have noticed something, little master…" He touched the lightening bolt scar on Harry's forehead. "There is an intruder that shouldn't be here. If you will allow me to, I will take it out." Harry could only nod. The words that Sebastian had spoken were ones that he didn't understand. Sebastian smirked. "I will take you somewhere for the time being, little master. It will be painful to take this intruder out. We will then start working. I have much to teach you." Harry nodded and Sebastian picked him up again. The man then walked off into the darkness with Harry.