Ambivalence. Killua feels this way about many things. He's ambivalent about chocolate – he delights in everything about it except for its price. Once, he tried to explain this concept to Gon, although the effort fell spectacularly flat. "How can you like and hate something at the same time?" Gon doesn't understand, and Killua is ambivalent about that.
Seasons change. ... And Killua is swept along with it. But he knows, because Gon is beside him, that he doesn't mind a bit. What's the point in turning back time?
Snow falls. "Hey, look, Killua! It's snowing! Wanna make a snowman? All right! Wow, you even got a carrot for his nose! Wait, you swiped it from that guy's house over there? Oh no, we're gonna get yelled at!"
Craftsmanship. Killua regards the snowman with ambivalence. On one hand, it has an excellent carrot for a nose. On the other hand, the body is lopsided and after a few minutes of watching, its head slides off onto the ground where it forms a pile of soft, powder-like snow.
Foolhardy. Normal boys get bored of games very quickly. Half-attempts at snowmen are evidence all around them. But Gon doesn't give up until his snowman can stand upright with a smile on its face.
Prior infiltration. For all his upbringing as an assassin, Killua is very much a normal boy. He used to get bored so quickly of waiting around for nobody to come.
Post Infiltration. When Gon and Killua finish their snowman, Gon exchanges a wink with Killua. "I couldn't have done it without you!" he says, and Killua replies, "That's because you have no sense of proportion."
Extraordinary. Gon squats and examines the snowflakes that brush against his hand. He finds them indubitably fascinating.
Exchange. "Is that what you always did as a kid?" "Haha, yep!" "That seems... kinda boring, actually." "What did you do, Killua?" "Killed people."
Digression. A snowflake falls on Killua's hand, barely distinguishable against the paleness of his skin. He peers at it for a while. Then he flicks the snowflake away. It is gone forever.
Backdrop. Killua is ambivalent about his past. Apparently, there's a whole lot of mysticism about the Zoldyck family, and in spite of his sensibilities, he finds them pretty cool.
Family matters. He's never homesick, not in the traditional sense. He wants to live without them and the inexhaustible shadow they cast, to live how he wants to live, even though he hasn't quite figured it all out yet. Maybe this is how a rebellious princess feels about the royal family.
The edge of truth and lies. He hates to think that they understand him and he shudders to consider that Illumi's words have a ring of truth in them.
Wan moon. Gon is tired when the moon rises. He sleeps, and Killua wonders if he should be disappointed at how hard his friend kicks in his slumber.
Displacement. When Killua was young, Illumi used to ambush him with knives in the early hours of the morning. Since then, Killua has gotten used to sleeping lightly.
Condensation. Sometimes, when the clouds obscure the sky, it's like the dawn of nightfall. Killua is ambivalent about this too. Night is when he is most comfortable and when he can move around freely in the shadows, unable to be detected by the human eye. But then the clouds move on and the shadow passes. Maybe next time it will rain.
Light and dark. If Killua is dark, then Gon is light, and sometimes, Killua wonders vaguely how they even get along. And Killua is not sure how he feels about that.
Impending. Everything might come crashing around his ears one day.
Presentiment. But tonight, Killua is tired.
Vindication. In his sleep, he probably kicks Gon just as hard.