Summary: Mathias and Leon are the new patrons of Cross Academy. Kaname knows nothing about them. Can the vampire Prince find out using his pureblood status? Why is Zero always caught in the middle of politics?

Disclaimer: Castlevania belongs to Konami and Vampire Knight belongs to Matsuri Hino-sensei.

Warnings: Blood, Violence, and Sex (in later chapters), possible polyamorous relationship

Authoress: An idea I have been playing with for a while. Despite the manga ending, I still have lots of love for the Vampire Knight series and the great fanfiction it inspired I was replaying Castlevania when I thought about putting these two together. It's never really mentioned what time frame or country VK takes place in right?

Sharing a Kingdom

Ch.1: Not the Only King

Inside a grand castle, moving was taking place. The castle was a vast space, taking up the majority of the cliff it was situated on. The walls of the castle were made of the oldest black stone with green ivy over grown on the four watchtowers it possessed. The castle was isolated as acres of woods surrounded itself and its masters from prying eyes. The castle housed two Kings of the Night.

"Mathias," Leon sighed. "Do we really have to move?" The blond vampire sipped from his crystal glass of blood as he walked towards his mate.

Mathias was looking over the gremlin movers as they packed the second moving truck with their furniture. "Careful!" He yelled when one mover bumped the corner of an antique display cabinet. "Leon, how many times do we have to argue about this?" Mathias turned to face his mate, "If we want a new life, we have to move."

Leon lifted the glass of blood again to his lips. After another drink the blond vampire said, "But, so far away?" He was giving his mate a dissatisfied look that Mathias liked to call Leon's pout.

"Don't worry, my love." Mathias wrapped a possessive arm around Leon's slim waist. "While our new home may not be beautiful Romania, it will still be European enough that we will adjust quickly." Mathias gave Leon's pale cheek a kiss. "Plus, we'll be surrounded by creatures of our kind—albeit a different species."

Leon sighed again dramatically, "A school of all things? Why not tailor shops? Or maybe a hotel?"

Mathias gave a small smirk, "I thought it would be fun. Besides, it's a school working towards co-existence between vampires and humans. Shouldn't you be happy?"

"I guess…" Leon smiled. He could never truly be angry with Mathias. They've been together for over two thousand years. Leon was about to complain about traveling there when a mover accidentally dropped a chest onto the floor. The black chest with intricate gold painted vines and leaves broke into tiny wooden pieces. "Hey! That was my favorite chest!"

Mathias laughed as he watched his mate chew out the mover verbally. He was couldn't wait to start his new life with Leon in Germany.

~*Sharing a Kingdom*~

Zero grumpily wondered why he was summoned to the Chairman's office during class. Not that he was paying attention in class anyway. Once he reached the grand oak doors of the Chairman's office, Zero knocked a few times. Hearing the "Come in." of his adoptive father, Zero entered, stilling as he saw a certain pureblood. "Kuran." Zero said with every ounce of contempt he could muster.

Said pureblood nodded his head in stiff greeting. "Kiryu." Kaname's voice was emotionless. The pureblood was sitting in one of the office chairs directly in front of the Chairman's desk.

Once Zero got over his bout of anger, he closed the Chairman's door slowly, hearing a soft click. But instead of sitting down as his adoptive father indicated with a silent nod, he crossed his arms over his chest and looked directly at the Chairman. "Well, Chairman." Zero said sarcastically. "What is this about?"

The Chairman gave a comical sigh. "Well my dear lovable son, to cut it short, someone has bought the school."

"What?" Zero's silver eyebrows furrowed in confusion. "How?"

"Kaname-kun and I were just informed by both the Vampire Council and Hunter's Association that the new patrons of the school are vampires coming from the Romania." The Chairman said calmly. "It's said that this was a way to bring new funding to the school as the patrons are apparently filthy rich."

Zero's face still showed confusion at this revelation. "But why? Isn't the money from the students and the vampires already enough?" The school hosted nothing but the aristocracy from both worlds. The co-existence program also had separate funding from both the Council and Association. Money was the least of their worries.

"It was a political move." Kaname spoke up. "It was the Council's way of trying to gain influence over the program. They know they cannot overturn my authority, so they are trying to throw a bigger wrench into the equation."

The Chairman adds, "I believe the Association also agreed with this to undermine Kaname-kun's authority. Despite having to get help from vampires, this is also an opportunity for both parties to prove that the co-existence cannot work."

Zero leaned his back against the door. "So, who are these new vampires?"

"That is the problem." Kaname stood up and began to pace. "These are vampires from the East. They are outside of the Vampire Society here. I'm surprised the Council is so desperate as to get foreign help."

"What? There are vampires outside the Vampire Society?" Zero asked. He didn't know that. In the Association they were only taught about the Vampire Society as all of the vampire population.

"Yes." Kaname answered simply. "There are vampires who are not of our species, and also vampires who claim no allegiance to the blood lines. We call these types of vampires Black Bloods."

While Zero's face was his usual ice mask, inwardly he was freaking out. He knew nothing about these vampires and either the Association was withholding information from their hunters (which was normal) or they had no idea either. "There are different species? Chairman, you know all about this?"

The Chairmain folded his hands together and leaned his head atop the fists. "Yes. Not many are authorized within the Association to know this type of information Zero. Kaname-kun has disclosed to you this important piece of information about vampires as he chooses you to keep an eye on the patrons."

"Me?" Zero lifted himself off the door quickly and unfolded his arms. "Why me Kuran?"

"You are a hunter and also a vampire Kiryu." Kaname pauses his pacing. "Must we go through this every time? You are the only one with the ability to enter both vampire and hunter societies—with some trouble of course. You also have powers from both worlds and have killed two purebloods. If anyone has the ability to spy on the new patrons, it's you."

"But—" Zero started but was interrupted by the Chairman.

"Zero, this is very important." The Chairman said gravely. "Right now, you are the only one who can help us in this political power struggle. If these new patrons are really working with the Council and Association, it means trouble for all of us: the Night Class, the Day Class, me, you, and Yuuki." Chairman Cross knew he was playing dirty with Zero by bringing in Yuuki, but it was the surest way for him to get the stubborn hunter to help the cause. "You are the only one we can trust."

A moment of silence passed. "Fine." Zero grudgingly agreed. "What do we know about these vampires?"

"The patrons are mates, both male." Kaname states. "And obviously they fit into the Black Blood category."

"I couldn't gather any information from the Association." The Chairman says dejectedly. "All I know is that they should be arriving this Sunday to check out the school."

"That's a load of information, thanks." Zero says as he turns around to open the door. "If that is all, I'm going back to class."

"Kiryu." Kaname calls. Zero pauses in the doorway, halfway closed. "Be on your guard. For Yuuki."

Zero silently closes the door after himself.

~*Sharing a Kingdom*~

It was Sunday evening. The night was magnificent. It was winter and snow covered the school ground like a blanket. The moonlight reflecting off the frozen fountain water, trees, and flowers made it look like a scene from a fairy tale.

Zero, the Chairman, and Kaname were standing by the circular driveway in front of the Chairman's house as they waited on the patrons. Everyone was bundled up, as it was cold enough to freeze water instantly.

Zero adjusted his gray coat over his black Day Class uniform. The Chairman made him dress up as they would show the patron around the school grounds. Personally, he didn't understand why they couldn't wait inside. He peered at the other two from the corner of his eyes.

The Chairman was wearing his signature purple scarf around his neck along with his beige trench coat. He had a contemplative look on his face while he stared ahead. Kaname had on his white Night Class uniform with a black pea coat. His face was impassive as usual.

Just when Zero was thinking of going inside the house to keep warm, a black limousine pulled up. The tension in the air increased ten fold as the limousine parked in front of the trio, and a black haired man got out from the driver's side. The driver was a vampire, Zero could tell from the aura. However, it was a different aura than what Kuran exuded. The driver had the usual vampire handsome face and was finely dressed for a servant. He had on a black suit with gold embroidery on the collar, cuffs, and buttons of the jacket. The driver came around the limousine and opened the door.

Zero's breath silently hitched as the assumed patron stepped out the car. The man was also a vampire—the same type of vampire as the driver. He had platinum blond hair that curled into light wisps around his neck. His eyes were a startling blue, a blue clear as the ocean in the Caribbean. His skin was as pale as the snow covering the ground. He stood slim and tall but with lithe muscle Zero could see peeking through the thick fur coat. Damn. Zero thought. That was really all he could think.

Meanwhile, Kaname was having a similar reaction to the beautiful patron. The pureblood swore this man had to be a siren. The patron was more beautiful than half of the vampire women population he knew. Kaname could also feel the air of a leader and warrior from the blond vampire. There was an aura that screamed "old world" around him. Unconsciously, Kaname straitened his back. This vampire was dangerous.

"Thank you, Armand." The blond patron spoke to the driver. The driver closed the door and bowed. The patron then turned to the trio. His azure eyes roamed over the three before landing on the Chairman. "Are you the Chairman?"

All three were tripped up by the smooth voice. The Chairman coughed, "Yes, I am. My name is Chairman Cross." He held out a hand.

The blond vampire shook the Chairman's hand. "My name is Leon Belmont. I am only one of the patrons. My husband Mathias couldn't be here as he is meeting with the Council and Association at the moment."