Things to know: Doesn't really take place along any specific point of canon

Sociopath
An individual who is in repeated conflict with society, does not feel guilt, does not learn from experience.

"Killua!"

Gon's agonized yell echoes in their hotel room, ricocheting in the large space and startling the people in the rooms around him. The voice reeks of indescribable pain and rage and betrayal, tearing sympathy from their chests like still-beating hearts. It's an animalistic cry. It's an exposed cry that resonates in a way only a few can truly understand what it is.

Killua simply laughs as forges on ahead. He easily swats the pillow Gon throws at him with an absentminded flick of his wrist, his grin taking on a razor edge, and it tears through the room and takes out one of the few remaining, unbroken lamps on its way to smashing against the wall, bursting into a mess of feathers.

Desperation lines every part of Gon's body as his mind works furiously against the inevitable end, time running out and resources low. Killua's eyes already sing of victory, which only makes Gon try harder to get out of the corner he's been backed into, hands clenching so tightly the bones begin to crack.

Gon turns wildly, weaving back and forth along the allotted space until…he's passed! He's passed Killua and home free, going as fast as he can, the victory yell ripping itself from his throat even as Killua snarls in annoyance, hot on his trail, but he won't catch Gon. Not this time, with the goal so close he can nearly taste it—

He's hit from behind. It's so quick, barely a warning before it hits him, flipping him off balance and dazing him. It doesn't matter how long. Killua only needed a second, and he's got it. Gon's lost. It's over.

Killua grins.

(The more time Gon spends with Killua, easier it becomes to forget Killua is from a family of assassins. He's the opposite of everything Gon excepts when he hears the word "assassin." He's not dark, he's not broody… not like Illumi at all. It's hard to relate the childish, chocolate-loving, fluffy-haired boy with the image of the killer standing in trick tower smirking over a dead serial killer.

But other times, Gon will catch a glimpse of it, and it will remind him of that image of cold, distant person who feels nothing for the lives his taken. No guilt, no shame, no remorse.)

The TV's victory song is overshadowed by Gon throwing his controller against the wall. The resulting crash is deafening. "You cheated!" Gon screams, jumping to his feet and glaring down at the boy screeching in victory, Killua's whole body going limp as the tension leaves his body.

"You can't cheat in Mario Kart!" Killua laughs gleefully from his position on the floor.

"That red shell was bullshit! Bullshit!" Gon grabs a cushion from the couch. "You were in first place when you got that! I was in second and got a coin. A coin! That's! Not! Fair!" he yells, hitting Killua to accent each word.

"Ha! Not my fault the game hates you!" Killua holds his arm up to defend himself as he mashes the A button with his other to get to the results before Gon can break the console. "And look at that. I got gold!"

The TV displays the results proudly for all to see: barely triumphing in first is Killua, his player's bar highlighted in yellow. In third place, only two points away from first, sits Gon's blue bar.

The resulting crash finally convinces a woman next door to call the front desk. At eleven o'clock at night, she fears the worst.

When staff finally gets into the room at eleven o five after banging on the door and receiving no answer, they find two boys wrestling each other on the ground, the pale one still smiling in triumph even as the other smacks him in the face with the shredded remains of a cushion.

The longer they look at the scene the more panicked the staff become. None of the pillows or cushions have survived the onslaught. Shreds of colorful fabric are all around the room, mixed with feathers and white cotton stuffing and glass. The painting on the wall is crocked; embedded in the space beneath it is a Wii controller still in the wheel attachment. The couch is upturned, the curtains are a mess, bits of food and stained plates are littered in front of the TV, which is remarkably the only thing untouched by the barely contained chaos still rolling around on the floor.

"I want a rematch!"

"You're still a loser—"

"Says the guy who used Dasiy!"

"What does that have to do with any—"

"YOU TWO!"

Gon and Killua both freeze.

"GET OUT!"

"Move over."

"I'm gonna fall off! Give me more of the blanket."

"It's not big enough!"

Both boys huff in annoyance, their knees banging together painfully under the covers. The draft slips between the sheets and forces them closer together for warmth. Any other day at any other time they might have welcomed it, accepted it even, but instead of sleeping in a nice, fancy hotel they had booked, they were stuck in an old abandoned apartment with barely any space for the two of them. Neither of them are in the mood to be in the same room, let alone the same bed.

"I'm finding my own room and bed tomorrow," Killua mutters sleepily.

"Good," Gon says, "don't let any red shells hit you on the way out."

"Oh would you stop and go to sleep!"

"You cheated!"

…

"Idiot."

"Jerk."

So I realized most of these chapters (and chapters I haven't published yet) are very angsty. I thought I'd add in something a little more…happy.

Thank you to everyone who's been reading! The next update shouldn't take nearly as long as this one.