Vis-a-vis a discussion about what he did in the Blackwall thread (I paraphrased the exchange that I heard between him and Cole, and then Credulous found the actual dialogue):
So to everyone who seems to be declaring him a heartless bastard, etc., what you fail to recognize is that the man who hired him lied to him. Yeah, he took money and used his own men for his own gain, but I'm under the impression that he thought it was going to be your average Game-related political assassination - and I would guess that this kind of thing happens regularly in Orlais. At this point, we all know that it's just the way that Orlesian politics work.
At the last minute, and presumably he was there with his men, Rainier heard the children's voices in the carriage and realized in that moment that he'd been lied to by the man who hired him. He probably wanted to stop things, but it was way past too late at that point, because he was effectively screwed either way. There is no doubt that Rainier of the past was a self-interested pr--- who only sought his own advancement, but he changed - a lot - and ever since then he's been trying to make up for what he did.
Also, regarding Revelations, if Blackwall/Rainier were really the same man that he once was, he would have run. But he didn't, and he even saved one of his own men from hanging. And frankly, you should probably take Blackwall and Cole with you after Revelations to hear that banter for yourself - the delivery alone when he begs Cole to stop ought to tell you the truth of the matter.
Cole doesn't lie, and he sees right into everyone's hearts. And as someone who romanced Blackwall, I realized that the man that he was then and the man that he is now are two very different things. I certainly didn't forget what he did, but I also considered everything he's done since that crime (including when he helped those fishermen learn to fight for themselves). I gave plenty of people who messed up second chances - like taking Alexius (the guy who tried to kill us) on as an agent because of everything Dorian told me about his situation. There were, I thought, sufficient extenuating circumstances in his case. Ditto on giving the Wardens a second chance even after the blood that was spilled, because I could understand that they were really scared and had done something stupid because of it. They really screwed up, but it did not wipe out all the good they had done in the past, etc.
Great post Atreiya - I agree entirely.
Honestly, I can understand people hating Blackwall after finding out the truth. I was shocked and disgusted too. BUT it's important to remember that until the very last minute, he believed the lord he'd been sent to kill was only travelling with bodyguards. So while his actions would still have been wrong even then, he didn't know there were women and children in the group until it was too late, and when he DID find out he wanted to stop things but couldn't.
I actually think this acts as a parallel to the story he tells the Inquisitor about seeing the group of children torturing/killing a dog when he was younger. In both cases, he wanted to prevent something horrific from happening but was too much of a coward to act. So it makes total sense to me that when starting his "new life", he decided to become someone who, to him, seemed the very embodiment of bravery and selflessness.
So yes, what he did was inarguably wrong, but he's clearly been punishing himself for it ever since (judging from his dialogue with Cole and the clear examples of self-loathing he demonstrates when you go back and rewatch some of his earlier conversations with the Inquisitor). And though he ran, he did try to atone for his crime by acting as a Grey Warden and protecting those in need (heck, his introductory scene is him training a group of fishermen to protect their homes from bandits). He isn't the person he once was.
Anyone still doubting the sincerity of his remorse should read the following conversation between him and Cole, who, after all, sees the truth of everyone's pain:
Blackwall: Cole. If you know what I am...what I'd done...why didn't you tell the others?
Cole: Everyone hides dead things. Everyone pretends. You wanted to fix it.
Blackwall: I'm a murderer.
Cole: You don't want to be. You made a new you. You ARE Blackwall. You killed Rainier.
Blackwall: If only that were possible.
Cole: You would stand between Rainier and the carriage. But you can't. It doesn't work like that. So you carry the bodies to remember.
Blackwall: I suppose I do.
My Inquisitor forgave him. Not just because they were in a relationship, but because she knows he's a good man who once made bad choices and now wants to redeem himself.