Arya, tormented by her own ghosts in those catacombs, had been able to confront the figures of her murdered family and walk away from them. With some prompting. A part of Roland's mind considers trying the same thing here, but not for more than an instant. Demanding something of Aang which he can't give - and Roland is sure, right now, that he can't - will only make all this worse on the boy, and probably make him resent Roland on top of it. Those two figures of Aang's dead aren't the real problem here, anyway. Roland spends a second thinking on that problem, and how to begin untangling it.

"Are you charged with saving everyone? Strange thing for a Capitolite to tell someone who's about to enter an arena." Roland knows, of course, that Aang was thinking of his own world when he'd said that, although you couldn't tell it from his tone. But he is making a point, one that will be more effective if Aang makes the realization himself. Might not help much, of course, but it'd be a start.