"True enough," Noctis agreed, his expression just slightly serious. "That's when you'd pay them back for all of their body-guarding. When have monsters given us much trouble?"

Emphasis on slightly - he's still just being a bit silly, in the end. They were far from invincible - the last mission had proved that. His going into Stasis had proved that. But so much of their time on the road was pretending to be fearless, as if being on the run wasn't dragging them down. Their time on this train wouldn't be much different.