Wataru summoning Ryujinmaru for the very first time.
Xelguard unleashing the Evil-Cleaving Light attack for the very firsttime.
Gurren Lagann single-handedly enters and weakens the intensity of a tornado with its drill. Simon is clearly weakened after doing the impossible but Viral soon shows up to give Simon some words to fire him up and joins up as Gurren Lagann's co-pilot.
Might Gaine being formed for the first time in the game.
Stage 16-A. After the battle against Black Might Gaine, Nia arrives to tell the X-Cross that Black isn't evil, but is being mind-controlled. Hoi Kow Low tries to kill her, but Banjo and Daitarn 3 stop him. Purple arrives and reveals his goal is to force Maito to Shoot the Dog, in a bid to shatter his resolve, and Professor Wolfgang reveals that the mind control device is too deeply embedded to be removed. As Black goes berserk fighting the mind control, Maito is considering if he really has to do it when Banjo steps in.
Banjo: Are you really going to make such a foolish choice? Maito: Huh? Banjo: You know, I don't have the ability to pull off a cool win whenever it's convenient...But if you're a hero, making miracles happen is part of your job description. Maito: I...I'll bet on a miracle until the bitter end! Wake up, Black! I know a heart of justice beats within you!
With the encouragement of the X-Cross, Black Might Gaine manages to break the mind-control device, allowing him to join the heroes. He even gets to do his own fully voiced version of Might Gaine's In the Name of the Moon.
Might Gaine: Black! Tell us the thoughts resounding in your heart! Black Might Gaine: You got it, brother! Carrying hopes on black wings, the green light signaling peace shines! The Brave Express, Black Might Gaine has arrived right on schedule!
As it has been tradition with the previous games that featured Tomino-directed Gundam shows, most of their pilots may swap their robots with one another, complete with new voice lines for attacks that require or feature a name-calling in that unit. Such was the case for the ZZ Gundam's High Mega Cannon.
Lelouch’s debut and resurrection of the original Zero. Powered by so much charisma that even the Norma are unnerved by him, convinced that he cannot be a good person (well, except Ange, who claims not to dislike people who don't choose the means to reach their ends).
In the next Scenario afterward, instead of just Ange trying to sneak her way into Misurugi to find Sylvia, the entire X-Cross fleet blows their way in with Lelouch and Nemo carrying out the whole operation.
The whole startup is an awesome moment for Lelouch, too. Most people could only say "good luck" or would normally try to stop Ange. Leouch, on the other hand, simply walks up with confidence, points out the flaw on her plan, and offers the much better one with the resources at their disposal. The very proposition stuns Ange so much that she thanks everyone. And this is not a typical sarcastic "thank you" she gives either, but a true expression of gratitude for everyone's help.
Salia: Wow, an actual "thank you."
Amari/Iori shows the Misurugi soldiers what a magic-user can really do on foot.
"It's bad enough that your endgame is pathetic, but you're standing there acting like you've won, and it's just hilarious. Did you honestly think that I'd stroll right into a trap I saw coming a mile away without even bothering to prepare?...Know this, incompetent king of nothing! I am Zero! Destroyer of the evil that lurks in Al-Warth!"
In his debut stage, Heero shoots Bellri with the Twin Buster Rifle while the G-Self is equipped with the Reflector Pack to power up the G-Self. Yeah, that same Twin Buster Rifle that can destroy bunkers and a colony was tanked by the Reflector Pack.
Stage 33 of the Doakdar route has the Brave Express Corps working together to unleash the Joint Dragon Fire attack.
Stage 33 of the Misurugi route has Seabook releasing the limiter of the F91 to stop Char. Bonus points for Char joining the team moments later.
Stage 33 of the Misurugi route gives us the epic entrance of the G-Self equipped with its Perfect Pack.
During stage 34 of the Doakdar route, if conditions were met, Show will unleash Bilbine's Aura Shoot attack and knock some much needed sense into Todd.
The long awaited arrival of the Hi-Nu Gundam on stage 35.
All of stage 36 is a Humiliation Conga for Julio. Who dies in his own palace knowing that he’s been used, betrayed by everyone he relied on (including Riza and Embryo, who still delivers the final blow), and above all...dethroned.
The same stage provides a villainous example in the form of Chris, who absolutely refuses to go down no matter how many times you shoot down her Ragna-Mail. If only it was for someone more worth it than Embryo. It doubles as one for the player if they're suitably well-prepared, as they can shoot Chris down over and over again to rack up massive amounts of money and Tac Points, an opportunity that very few games offer.
And who's the one that manages to finally get through to Chris? The "Boy-Ange" of the group, Lelouch vi Britannia.
Scenario 39 of Amari's route has Hopes/Spero piloting the Xelguard on his own to fight on his master's behalf. Iori even switches to the player's side almost immediately after Hopes/Spero calls him out for hurting Amari.
Alternatively, scenario 39 of Iori's route has Hopes/Spero betraying the team and creating a mirror Xelguard to fight Iori. Let's just say that the X-Cross and Iori gave Hopes/Spero a verbal and physical beatdown he won't soon forget.
Scenario 44 on the Doakdar Assault Group route sees the true or so it seems final showdown with Embryo in his pocket dimension, which the characters on that route have no means of breaking out of and in which he's completely immortal. Enter the Buddy Complex characters from the other route to save the day, followed by the player getting the pleasure of wiping the floor with 19 Embryos, all of them having a habit of clustering up nice and close for Ange to use her newly-powered-up Discord Phaser on.
Just like in Jigoku-hen, when the climactic showdown between Tengen Toppa Gurren Lagann and Granzeboma happens, everyone is at size infinity. Then Mazinger ZERO joins in the fun as an enemy in the IF route and all hell breaks loose!
You think Mazinger ZERO being an enemy is fun? Wait till he joins the fray AS AN ALLY UNIT! That's right! All three Mazingers are on the same side!
Hopes becomes the True Final Boss. Yes, the sub pilot of your Original Generation mecha from the very beginning of the game becomes the True Final Boss! And it ends up being a Batman Gambit as he utilizes the positive emotions that the heroes have to fuel Ende to secure Al Warth's future.
What's amazing is that for the first time in the franchise's history, we've had nothing but final bosses being an Omnicidal Maniac, overprotective beings to the point of killing off the characters just because they disagreed, It's All About Me primadonnas, or that they did it For the Evulz. And while the Final Boss of the game is no different, the fact that the True Final Boss pulls out one massive gambit for the greater good of the world and uses the protagonist's positive willpower to fuel Al-Warth ends up becoming one of the most highly memorable final bosses in the franchise. And Hopes lives afterwards.
DLC Scenarios
In the "Phantom Butterfly" DLC stage, Hamada gets to pilot the Might Kaiser while Kocho is playable as well.