But not really a spoiler, because seriously, what happens to every single Wise Old Mentor character? Yeah, he dies early in Act One as a result of NPC treachery. The NPC companion Alistair, who looked up to Duncan and was mentored by him, is grief-stricken.
If this were a tabletop RPG, I bet doughnuts to dollars the GM (or another PC playing Alistair) that "grief-stricken" gets immediately translated to "rage and vows of revenge" against the betraying NPCs. Because anger is the one passion universally acceptable at gaming tables.
Alistair the Computer NPC is sad. His voice breaks and he chokes up. And it continues to be a difficult subject for him; one conversation with the PC does not miraculously make it all better.
On the other hand, he does not stop with the wise-cracks, either. Whether that's because the writers thought they were too cool, or they actually realized that grieving people do not become one-note representations of melancholy (that would be the second most acceptable tabletop interpretation), I don't know.
Dragon Age provides options for romance as well; I haven't really gotten there yet, but that's a subject that's notoriously difficult around the gaming table.
It probably shouldn't be a surprise: the Dragon Age avatars are digitally animated and voiced by professional voice actors, whereas gamers are... well, gamers.