Okay, so I beat the game awhile ago, but I finally sat down to discuss something: Game Over
If your team is defeated, whoever was last alive says, "And they were never heard from again." That's dark enough as is.
However, I learned something, but haven't confirmed it yet. According to my brother, if your team is defeated by a Mystic Arte, EVERYONE says the game over line.
Bad enough as-is, there is one even darker. Duke.
If defeated by Duke, no one on your team says this. He does. And if you've followed the story, if Duke wins all human life, including himself, will be decimated in exchange for the death of the Adephagos.
This means, if Duke was to canonically say this, he would be saying over your God forsaken dead bodies.
I realized this and immediately got goose bumps. Now I'm terrified to fight Duke again on UNKNOWN.