LogFAQs > #905180804

I think in this case it doesn't require too much logical explanation and works more as an expectation.

Gon is repeatedly said to be holding some scary potential from veteran hunters, and Pitou even takes him extremely seriously way before she should really have any proof he'd be dangerous. "His fangs may reach the king."

I interpret it as not a power up but more that Gon brought out his full adult potential. And we know that nen allows the user to attain great strength at great cost. Also Gon basically dies for this if not for alluka hax.

Edit: I actually don't know what I mean by that first line.
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