That's the thing. Solas doesn't think he's doing anything wrong and that makes him worse than Thom. How we are going to redeem him God only knows, but I do hope it's an option.
Maybe I need to look at Trespasser again, but the indication I got from Solas is that he knows what he's doing is wrong, that he deserves full punishment for what he's already done and what he's going to do, but - for whatever reason - he believes this is something he must do. You're right, how we go about redeeming him in a meaningful way is something I have absolutely no idea how they'll pull it off, but I hope we get to. x)
Thom needed an epic b*tch-slap to get over himself and stop hiding behind another man's glory so he could play at being noble and good himself. He did exactly that by the end of Trespasser for me, and it was only then I could see him as being redeemed. Not because he was helping others. Not even because he gave up on the self loathing and personal torture he inflicted on himself. In fact, it was that self loathing and torture that annoyed me. He wasn't doing it because he felt that bad about the whole thing. Certainly he regretted killing kids. But even the self-hate was part of "I SHOULD be doing this/feeling this way to make myself into a good and noble image." It wasn't real. He wasn't real, either as Thom or as Blackwall. He was just the barest echo of an ideal that he had no true concept of, try as he might to fulfill it.
He really was an interesting character, all things considered.
This, right here, this is what I don't like about Blackwall! Thank you for putting it into words! I know too many people who parrot around ideals and images without really knowing what they're really talking about, and it's always something that makes my first instinct be to leave him behind in his cell. Even when he handed himself in, I never felt it was because he wanted to do, but something he felt he should do.
And it's what I loved about seeing him in my latest PT after I'd given him to the Wardens, and makes me feel guilty about all the times I'd left him to rot in others. I loved that he went back to his real name and seemed to have accepted what he wanted to do in life. I'm considering going with a pardon on my next PT, I'm interested to see where that takes him. Great character.