You know what really got to me and left that ache of FEELS OH GOD WHY? The stuff about Meredith, and Samson's time serving the Chantry.
DA2 had its flaws, and one of those was only portraying the extremists who lit the spark for the mage/templar war. It barely touched on all the people who got caught in between. All those years playing as Hawke, seeing Meredith squeeze the mages, and Samson's story showed us a glimpse of how badly it affected the other side. It wasn't just the lyrium, or her sword. The whole atmosphere of the Gallows was poison, pure and simple, long before the lyrium idol even reached Meredith's desk. The whole system was already rotten to the core, waiting for a push to send it toppling over.
For perspective: Samson had already been tossed out of the templars before Act One, with a reputation for lyrium addiction and sympathizing with the mages. Again, well before Meredith got the red lyrium sword. For all seven years of DA2, Samson was still trying to help mages like Feynriel. And look what he got for his trouble.
DA:I (and the tie-in novel Asunder) IMO did the best job of showing us the sympathetic side of the templars. And in a lot of ways, they're not that different from the mages. Samson wants the Chantry to pay for its mistakes, to burn it down and raise a new world from its ashes, and he knows he'll pay a terrible cost to do it. Sound reminiscent of Anders? I know there are people who hate both characters for what they've done, but honestly, I find it hard not to sympathize. If I'd been in Samson's shoes, or Anders', or even just a mage or templar living in the shadow of the Gallows...I'd want to take a torch to the whole thing too.
OK, done rambling. Gonna go hide in a corner with my feels and some gelato now.