Honestly, it’s when Charizard came back for his battle against Iris and her Dragonite

His role in the [Power of Us], [Distant Blue Sky], and [Koko].

I'm one of the few that believe that his AU-Movie counterpart is more interesting than his canon self.

Remember when he was lost in a freezing moment alone and his first priority was to save his pokemon and risked his own life making sure they wouldn't freeze to death back in the original series? Holds up.