It’s like in a math class where the kid with the highest grade (Killua) thinks he is the best in class then slowly realizing that another kid is actually a math genius (Gon) and the only reason they have a lower grade is because they keep forgetting to turn in their homework. It’s that “I work really hard to be this smart and I’m proud of that but this guy keeps one upping me and he isn’t even trying” vibes.
I think this is the dynamic that starts showing in the tail end of the Hunter exam arc and sort of ends by the end of the Heaven’s Arena arc.
This amuses me.

Hello hello! Are you ready to meet a nice little karate boy? Excited to find out what 'Heaven's Arena' is? Eager to see Killua get jealous because Gon makes another friend? Of course you are! It's time for the beginning of a new arc and the last Media Club Plus of the year, see you in 2024! ♡

Continuing drawing hxh characters based solely on the descriptions of them from Media Club Plus by @friends-table. This is Kalluto, Killua's brother.

Continuing drawing hxh characters based solely on the descriptions of them from Media Club Plus by @friends-table. This is Kikyo, Killua's mom