Kalas pulling a Big Damn Hero and rescuing Xelha from the Saber Dragon near the beginning of the game counts.
While held up in Lyude's former home by his brother and sister. Lyude mournfully admits that he can't bring himself to harm his siblings. So his nursemaid pulls out a gun and readies to face them in his place.
Almarde (fires off a warning shot) Next time I wont miss. I'm serious.
For this troper, the scene where Kalas rips the wing out of his back about midway through the game was so awesome and shocking, she stared at the TV for quite a while before continuing. Hell, the whole thing with Kalas working for Melodia came as a shock the first time I played it, a very daring move on the writers part.
When Melodia and Malpercio attack Mizuti's homeland, the Great Mizuti flies into a fury and unleashes a burst of energy so powerful that it nearly topples Malpercio.
Mizuti: I...I will never forgive you! Never, never never!! (cue super sayian like outburst of power)
Later, Mizuti's tribe tries to get a powerful artifact guarded by their (significantly more powerful) ancestors. They fail, and then Mizuti shows up and demands that the ancestors wait while Mizuti makes sure everyone is okay...and then takes the ancestors on and wins.
Gibari's Big Damn Heroes moment in Nashira, where he charges in and singlehandedly drives off a small horde of monsters.
Savyna and Azdar fighting the Palette Swap of Fadroh in the desert.
Lyude finally standing up for himself and forcing the Eldritch Abomination that created the Phantom Goldoba to reveal it's true form.
Xelha, who up until this point hadn't really done much other than serve as a foil to Kalas, stepping up and taking charge after The Reveal. She breaks out of the Imperial Fortress, rescues the other four party members from four Eldritch Locations, reveals herself to be the Ice Queen of Wazn, and finally invades Mintaka with only herself and her True Companions. This troper initially disliked Xelha, but after that, his opinion on her totally changed.
The powers of the four End Magnus have failed to breach the Cor Hydrae's shield. The monsters around the various shrines are attacking the rulers of the nations. Everything seems lost...and then the power of the fifth end magnus hits the shield, done by none other than Folon and Ayme of all people. With that power, the nations are able to breach the shield, starting the final level.
The entirety of Vega. After the Heart-to-Heart scene, Guillo and Milly show up to break Sagi out and escape. After a long dungeon, you get confronted by Shanath and his machina arma. After fighting him and losing, Sagi powers up with the Guardian Spirit and cripples his machina arma, then fights him again and kills him. The fact that you can use The Apotheosis to trash him both times is just the icing on the cake.
The Heart-to-Heart scene by itself is jawdropping. It starts with Sagi returning to present time, chained to an iron block in an Imperial stronghold. He asks what you are, demanding to know why you never told him any of this. As you share secrets with him, he puts the pieces together and begins to sink into despair, fearing you will overwhelm and destroy him. You reassure him, and together you merge your hearts and unlock Sagi's true power.
All three Big Damn Heroes moments in Tarazed. Heughes taking out a room full of machina, Nasca staying behind to keep a shutter open, and for the crowner, Valara swooping in on the Sfida to catch the falling Sagi and Milly.
Sagi: Go to hell, you son of a bitch! You hurt my mother!
Players should feel they accomplished one if they manage to defeat the super tough Bonus Boss Arma Prototype M in the Coliseum in a straight-up battle rather than relying on the Bomb. We're talking about an enemy so powerful, it can wipe the floor with you in a matter of seconds on its own, is so fast it's practically always attacking, and has an AI that seems to divine your strategy as soon as you think it! And it's backed up by two of the game's worst Demonic Spiders. If you can win this fight without cheesing it with the Bomb, you deserve a medal for your outstanding victory.