Joe's speech after finding out that Captain Blue was the villain.
Joe: "Captain... uh, KING Blue... You used to be cool. Now, you're nothing but a loser. I'm gonna show you what it means to be a TRUE HERO!"
King Blue: "Go ahead. I WILL SNAP YOUR FOOLISH LITTLE IDEALS IN HALF!"
Followed, of course, by a battle as Six Majin against King Blue on the surface of the earth... and the planet is visibly round, indicating just how freaking big the two are.
And after you do all that, you get treated to a duel against the original Captain Blue, in his youth!
Similarly, the final battle in VJ2 is essentially a mirror image of the first game's final battle, but subjected to an insane amount of Serial Escalation. You fight King Blue while spanning the earth's circumference; you fight Dark Kaiserin the goddamn solar system (with even larger mecha in the form of Six-Six; the boss itself is only surpassed in size by the sun itself), having to do mind-boggling stunts like punching planets with Mach Speed to make yourself immune to flaming dragons fired as projectiles, dodging streams of solar wind and X-rays, and hammering what is quite possibly the home planet of the villainous syndicate—which is embedded in the boss' chest—with your fists. It is ridiculously awesome.