A/N: Fill for a ficathon prompt. I liked it so much I decided to post it here. Lucky all of you, hurrhurr.

Vector is a little shit and I love him.

The rest of the Numbers Club stared at him in awe for his killer reflexes, but Vector kept his face clear and innocent, even if he was laughing inside. What was that? A projectile Kotori had thrown in Yuuma's direction? Oh, he hadn't even noticed.

Another time, he was distracted in class despite his usual eagerness to answer all of the teacher's questions (usually wrong), and he'd had to make a quick recovery. In revenge for the near give-away, Vector stretched lithely, kind-of-accidentally-on-purpose smacking Yuuma in the face. Fatigue from "staying up all night" made a great excuse for his demeanor that day.

Deception was an art form that Vector was proud to practice, if it was the only one he cared enough about to indulge in. Luckily enough, everyone who had a taste of it always seemed to appreciate the interest, in their own way - and each vicious new backstab was as unique and equally as enjoyable as the last.

Unfortunately, human bodies were infuriating at best. They needed constant sustenance, they slept in a set pattern, and they couldn't even regenerate from wounds over a period of minutes. Or even hours! No one in the school ever taking interest in his "home life" was a blessing for him, so he could take refuge nearly anywhere he wanted, and the only one who might have cared enough was-

"Shingetsu! Is that you?!"

Shit.

"Ah? Ahahaha, yeah, it's me, Yuuma-kun!" Vector whirled around, swathed from head to toe in a black cloak that thankfully was already hooded over his face. "Did you need something?"

"Nah, I was just curious where you were going! You never go home this way from school!" he laughed, making Vector's fingers twitch. He wanted to wring his neck so much, pop that stupid little head off so he'd never see that dumb grin ever again... "Er, what are you doing in that thing?"

"O-Oh, this! I was just thinking positive and trying out costumes for the festival tomorrow!" He lifted the hood up just enough to give him a line of sight at the people before him. Only shoes were visible from this angle, but there were two pairs of them, and one wore summery sandals - Kotori was with him.

"Shingetsu-kun, I don't think that suits you at all," she commented wryly. "You should try something... cuter!"

"Cuter?" the two boys echoed simultaneously.

"Yeah! You know what I think would look really great on you?" There was a smile in her voice as she pulled out a magazine with an article about cute but useful monsters.

Yuuma gawked. "Kotori, you read Duel Monsters Monthly?!"

"N-No, I just picked this one up at the mall because the cover looked cool! Jeez, that's not the point at all!" She waved it in her hand a little as she pointed to a leonine monster. "This one, Dandylion! He's really cute, and he matches your hair, too! You'd be great in him!"

"You really think so?!" said the voice of Rei, while Vector growled in his head. The lengths he would go to to maintain the illusion... "I'll think positive and work on it right away! Thanks a bunch, Kotori-san!"

"Hey, Kotori-" Yuuma tried, but was cut off when Vector darted off and Kotori shouted sentiments of "good luck!" and "do your best!" at his retreating cloaked figure. "Kotori!"

"What, Yuuma?"

"Was it just me, or was Shingetsu... wearing a mask?"

"Huh?" A pause. "He must have been. It was a costume, you know!"

That night, as he conned students with his totally adorable charms out of leftover fabric and thread, Vector should have been cursing in pain at the number of times he stabbed himself with the needle, or at the almost-panic of being found out before the time was right, but instead, he couldn't stop giggling to himself from start to finish.

Suited him, she'd said. A cute monster suited him. He couldn't wait to see how cute she thought he was when he was taking her best friend's trusting little heart and stomping it into a million pieces right in front of her.