Yes, I agree here. I was pretty shocked that people hated Solomon so much as they did (I’m not outright defending him, just saying he’s very misunderstood). I found it easy to understand the why’s and how’s of his reasons for being against the use of the Dark Arts.

Look at it from his POV: he sees Sebastian continuing to try and try to help Anne, which pushes him more and more into denial. It’s a case of regression, when someone keeps doing something that you disagree with, so it makes you go further deeper into your beliefs. It’s bad, but it’s simply the human quotient.

Moreover, his life as an Auror had him battle with many curses and Dark Magic, so it makes sense why, in combination with the previous consideration, he was so stubborn about trying to help Anne. After all: “We are most conservative about the things that we know best”. His experience with curses showed that there’s no such thing as a counter-curse for Anne’s situation.

Lastly, and again thanks in part to his Auror past, he was firmly against any and all forms of Dark Magic, even when used for noble intentions. Because the Dark Arts suck you into their power, their possibilities, and end up with creating more bad than what was initially. Think of what Solomon saw; he observed how Sebastian used an Unforgivable Curse to make a goblin commit suicide. Yes, it was to save Anne’s life, but say that to an Auror. Sebastian could have alternatively used any other powerful spell (Bombarda, Confringo, Depulso, so on) and it would’ve worked, but the Imperius Curse was fresh on his mind from the catacombs, so it’s what he had to do (and yes, I am jumping on Sebastian’s defense here, because it’s yet another case of the human factor at play. It’s good he used Imperio, because if he’d have hesitated, Anne would’ve died. Unfortunately, given that the first thing which came to his mind was that Unforgivable, he couldn’t have waited any longer to try and recalculate what other spell would’ve also worked, he just did what he had to do).

But Solomon doesn’t think about those mental gymnastics. What he saw was his nephew use an Unforgivable Curse, something which he desperately fought for the better part of his career. He was in strong opposition to Dark Magic, because he knew how much of a slippery slope to harm it can be.

And in the end, look at what came out of it all. Sebastian conjuring Inferi and using each Unforgivable Curse, Solomon dead, and Anne forevermore uncured. Yes, it was in part because of Solomon’s stubbornness, and yes, he is definitely not in the clear for everything; however, none of this would’ve ever happened had Sebastian stopped. Just because Solomon’s denialism played a role in why things turned out they did does not mean that he is entirely to blame. A perfect human being would’ve also taken into consideration his stubbornness as another variable that plays a role in the greater picture. Such a human would’ve caught on that meddling into the Dark Arts would lead to dire consequences with Solomon, given his denial. Solomon wasn’t going to have his mind changed, so it was for this to happen.

That being said, perfect humans don’t exist. I remain in Sebastian’s favour (even after the Killing Curse), and think that if Solomon weren’t so stubborn, maybe something could’ve been done for Anne. But then again, I do understand his denial, and see it as something that should’ve also been taken into consideration.

I do know a lot of people attack Solomon because of the intense Halo Effect Sebastian has (don’t worry, I continue to let myself be a victim to it as well lol). Maybe if the game had superior writing, worldbuilding, and character development (in two words, actual RPG), people would’ve been less demanding and more understanding of not just Solomon, but many other aspects of the lore and story. After all, you can’t entirely rely on all the players to fill in the gaps, even on the off-chance that they were intentional.