Disclaimer: (said in one breath) I do not own Harry Potter, Yu Yu Hakusho, Yu-Gi-Oh!, Sailor Moon, Cardcaptor Sakura, or Naruto, but I do own Checkmate and her crazy, mixed-up, mashed-up, physics-laws-breaking powers.

Summary: YYH/YGO/CS/SM/Naruto/HP crossover (Brief explanation of each plot given in the story!) Their worlds aren't as fun to watch when they're separate, so someone decides to mix them up. Watch as lives are rewritten and the laws of physics become mere suggestions.

You can skip most of this if you know all the stories. I've starred what is from me, so DON'T MISS THAT! It is CRUCIAL to the story! And you find out who'll be there in the last sentence of every paragraph. You don't want to be overwhelmed by the number of characters or be waiting for people who aren't coming, now do you? And you HAVE to know what's happening here.

Prologue: Checkmate

There was a porcelain doll sitting on the girl's lap, which she continually stroked as she observed the floating chessboards. Each held an array of a multitude of colorful characters that properly belonged in a role-playing game, not on such a traditional board. The tiny girl lifted her hand and touched one of the pieces. The figure had wildly long black hair and markings all over its muscular body. The girl began petting it, empty eyes fixed on the board.

"Urameshi Yusuke," she said softly. "Reikai Tantei, Spirit Detective. His gift is with the Reigun, the Spirit Gun, a burst of spirit energy which decimates most enemies. His teammates are Kuwabara Kazuma, a powerfully aware human;" her hand moved to a figure with an orange sword in hand and even more vividly orange hair, "Kurama, a kitsune;" she touched a red-haired figure holding a rose; "Jaganshi Hiei, son of a Koorime;" she touched the small black-hared figure. "He knows many psychics, and he knows the famous psychic Genkai," and she touched the smallest figure, a pink-haired, brown-eyed woman. "His… boss… is Koenma, prince of the underworld," and she touched a toddler that was only taller than Genkai by virtue of his impressively large hat. "We choose… the Tantei team, Genkai, the demons Jin, Touya, and Rinku; and the psychics Gamemaster, Doctor, Mitarai Kiyoshi, Hagiri Kaname, Kido Asato, Kaitou Yuu, and Yanagisawa Mitsunari… to participate in the coming game."

She moved her attention to another chessboard, apparently not noticing as the chosen figures vanished from the board to a new one which had not previously been there.

"Motou Yugi," she whispered. "Possesses the Millennium Puzzle, which when assembled appears to be an upside-down pyramid and contains the soul of an ancient Egyptian pharaoh. The other items of interest are the Ring, which belongs to Ryou Bakura and the inhabiting spirit Bakura, King of Thieves; and the Rod, which after belonging to Ishtar Malik and splitting him, creating Marik, has found its way to Kaiba Seto, president of a multibillion dollar gaming industry. We choose these four… seven… to participate in the coming game."

Another chessboard was selected.

"The ninja Uzumaki Naruto." Her voice this time was slow. "Carries a demon fox within him. While it is bound by a powerful sealing spell, Naruto has begun harnessing its energy, sometimes unintentionally. His teammates are Uchiha Sasuke," referring to a dark-haired boy, "and Haruno Sakura," a pink-haired girl. "Their teacher is Hatake Kakashi," who was a gray-haired man with his headband over one eye and a covering over his mouth. "Other shinobi are the sand ninja Gaara, Temari, and Kankurou; the second-year leaf ninja Neji, Tenten, and Lee; the other newbies from hidden-in-the-leaves: Hinata, Kiba, Shino, Ino, Shikamaru, and Choji; and the sound ninja Dosu, Kin, and Zaku." The doll's face caught the light as the girl's eyes glittered. "We choose all of them to participate in the coming games."

Now only three boards were left. The girl touched the blond ponytails of a figure on the middle board. "Tsukino Serena," she said. "Sailor Moon. She is responsible for saving the world many times, along with Anderson Amy, Hino Raye, Lita, and Mina." She touched each of the Sailor Senshi in turn. "They hail from the first five planets of the solar system, all but Sailor Moon. She, their princess, is of the moon as her name suggests. Her prince, Darien, is from Earth." She touched a dark-haired boy's figure. "Darien and Serena are destined to fall in love and have Rini, the princess of Crystal Tokyo." Rini was a tiny figure with pink ponytails. The girl leaned forward. "We choose all of them to participate in the coming games."

The next board had relatively few characters. The girl touched each one before settling on a small girl with short brown hair and an eternally happy smile. "Kinomoto Sakura," she said with more breath than voice. "The most powerful magician in her world. Master of the former Clow Cards, now Sakura Cards, and of their two guardians, Yue—" who was a tall, silver-haired figure with wings "—whose temporary form is Yukito, and Cerberus," who turned out to be a golden lion with a metal adornment instead of a mane and with wings identical to Yue's, large, feathery and angelic, "whose temporary form resembles a stuffed animal. Her brother is Kinomoto Toya." Toya had darker hair than Sakura's and was much older. "She loves, and is loved by, Li Syaoran." Syaoran was a boy with a rebellious expression and brown hair. "He is a descendant of Clow Reed, who created the Clow Cards and was reincarnated as Eriol," a black-haired, gentle boy about Sakura's age, "and as Sakura's father. Eriol's new servants are Ruby Moon," an (apparently) female red-haired beauty with butterfly wings, "who disguises herself as Akizuki Nakuru, and Spinel Sun," who was a black panther with similar wings, "who resembles, when he so desires, a black cat with wings. Eriol loves, and is loved by, Mizuki Kaho," who was a tall, beautiful woman with brown hair and an oddly shaped bell. She put a finger to her lips in thought. "We choose… Sakura, Syaoran, Eriol, Mizuki Kaho, Yue, Cerberus, Toya, Ruby Moon, and Spinel Sun."

There was now only one board. The girl placed her hands on either side of the board and stared down at it hungrily. "Harry Potter," she said to a black-haired, green-eyed, bespectacled boy. "The Boy Who Lived." Her eyes roamed around the board. She smiled. "The battle will take place on a world like theirs. Theirs is the blueprint for the field of this game."

As the board fused with the one above it, the one on which the selected figurines now stood, the girl closed her eyes, took the doll's hands in her own, and spoke.

"Only that knowledge which is needed shall remain,

With no source for this knowledge these player's memories to stain.

Trapped within a different world, one not all their own,

Only to find the seeds of malice have already there been sown."

She looked down and chanted, more quickly.

"Let the wards now be broken

That the games may begin.

Let the doors all be opened

And the players welcomed in."

At once the board began to spin. When it stopped, the players were arranged in neat ranks along the sides of the board. Shadowy figures stood along the other side of the board.

The girl smiled and lifted the figure of the red-haired, blue-eyed, horned demon and the one with silver-and-green hair and set them down along the ranks. Her eyes glittered, a sight somehow not as frightening as the emptiness they had held in the beginning.

"Demons to E-7."

Well. That's the beginning of my super-creepy, super-weird fanfic. What do you think? Please review, even if you're just going to flame me. I don't want to waste my time on something no one likes. (Although I promise, you don't know half the story and it will involve the characters mentioned… in small groups, though, so you can keep track of them.)