A really odd CMOA is in the last stages of the Demon Path. Everyone is united and blades ready, speeches launched, their reasons to fight inspiring them to see this to the very end. It's what you'd hope what would happen in the Normal Path, and it pretty gives even the butt monkeys levels in badassery. The twisted part comes from the fact that they're united against you.
Dannette's reaction, if you lose, is especially awesome. She's sealed with you in the eternal prison, and sings to you.
The fight with Raksha. The whole thing is awesome, but the icing on the cake was the moment that many fans have waited the whole game for:
The final moments of the Normal Path. Drazil and the Gods of Life and Death, after defeating them in the final battle, are Not Quite Dead yet and to spoil your victory, they summon copies of themselves and blow one of your more powerful allies away. Even Revya with the extra power she gained from defeating Gestahl cannot stand against them, so what does she do? She finally decides to take Gig up on his deal and give up her body to Gig in exchange for the power to defeat the gods. What follows is the scene that firmly cements Gig as Nippon Ichi's biggest badass.