At this point I think it's safe to say that the ants are basically human at this point. Yeah, a lot of them are selfish assholes, but that seems to have more to do with their upbringing. At the same time, Gon was about to the the exact same thing he's mad at Pitou for. Killing a complete stranger to satisfy his own selfish desires.
Through his adventures, Gon has been able to fit most of his enemies into a box of pure evil. Genthru and Hisoka fit that label in his eyes. The spiders weren't really his enemy so much as they were just a threat to Kurapika. All the ants he'd met so far fit this label. And up until now, he thought Pitou was the same. But when he stows up after all the training and hardship and trauma he went through to get his revenge on Pitou, he is stunned to see him act so selflessly. In Gon's mind, this was an evil force of nature. But now he suddenly has to take in all this new information. The king had someone he cared about, that innocent person was hurt in the crossfire, Pitou wants to take care of this person, Pitou is willing to die for that purpose, Gon can't have his revenge right now unless he is willing to essentially kill an innocent child. All of these revelations, dropped on him at once, have to be filtered through the lens of his young mind while under the stress of limited time and the potential for death at any moment.
And the kid just snaps. He almost goes through with killing Pitou and dooming Komugi. Killua stops him, but Gon snaps at his best friend. Killua's fear of Gon's unflinching optimism betraying them has come to pass. Gon wasn't realistic about Kite's fate, Killua didn't try to change his mind, and now Gon is inches away from doing something horrible.
Throughout, the story is conveyed with the best art I've seen from Togashi. Gon's breakdown expertly capitalizes on the flexibility of Togashi's style, allowing him to really contort Gon's expressions and employ multiple art styles fluidly. It could be in my head, but I swear we're also seeing more full page or nearly full page panels, not to mention the double page spreads. The fact that these haven't been as common to this point really makes what is happening feel more grand and consequential than any previous point in the story.
And I want to give another shoutout to Knuckle, who feels like Kuwabara's ultimate form. He's become one of my favorite characters (and honestly more of a protagonist than Gon at this point).
Also another shoutout to how well explained each character's thought process is. Because we see them weigh several options at every juncture, their decisions feel believable and weighty. It really feels like things could go drastically differently because each option has been carefully considered. It also gives more of a feeling that things are playing out before our eyes because each character feels like a person trying to pick the best answer, rather than an actor in a narrative following their predetermined path.
One of my favorite examples is watching Youpi (the typical enemy dumb meathead) actively grow, learning self control in order to better serve his King. He goes from flailing wildly to playing mindgames by leaving intentional openings in his attacks. All because he realized that his previous methods prevented him from best doing what matters most to him. Knuckle does some growing too. And because we get such a window into each characters' thoughts, providing dramatic irony for both sides, it leaves you on the edge of your seat.
Fuck, this series got so good.