Goku's transformation in DBS Broly was pretty hype too at least the Eng VA, that primal scream was WOW!
Gohan's SSJ2 was built up from the beginning of Z, 184 episodes. Goku's Super Saiyan transformation? 55 episodes. So if you want to talk about number of episodes to build towards a transformation, both Goku and Gohan have Gon beat.
It's not just the number it's the narrative built around it, Gohan's build up has simply been "this kid as actually very powerful" Goku's was "oh yeah there's such thing as a super Saiyan"
Gon's build up dealt with psychological trauma, denial, murderous intent, rage, and emotional suppression in very real tangible ways relative to the series, his entire character development centered around these problems and how they were in part products of and intensified his character flaws.
And HxH actually used the "This kid is going to be extremely powerful one day" trope and flipped it on its head by introducing the aforementioned aspects to his character.
Gohan powered up because someone died in front of him and because been billed as this unspoken powerful kid. His power up came as a positive light from a tragedy.
Gon's transformation was a "this is bad" moment born from his anger, thirst for murder, broken heart, and being manipulated and lied to ontop of lying to himself and having to face the truth at the hand of the enemy who was the root cause for his descent.
I love DB and Gohan's transformation is so hype but nah it ain't touching Gon's
