The ending was going so well until Therion's final interactions with Lady Cordelia. It seemed that any progress he was making in becoming a more trusting character was ditched in favour of having him be the edgy "I don't show my feelings" guy that he'd justifiable been earlier in the game. He acts thankful for being trusted in, but proceeds to give Cordelia the cold shoulder for almost the entirety of the final cutscene.

While I'm at it, I want to voice an issue I have with Primrose's story. She gets stabbed, then the moment she wakes up nobody mentions it except for Alfyn in a banter segment. No asking if she's feeling better, or to be careful, or what the state of her wound is. She just leaves town as if it had no effect on her. Which would be fine, if someone had said within her plot about how her wound is. Without Alfyn, nobody would have brought it up. If someone is getting shanked in the gut and waking up fine three days later, at least tell me why that is instead of leaving it up in the air or relying on missable travel banter.

Because of course he's going to give her the cold shoulder. She's the one whom tricked him into doing her dirty work. To expect Therion to suddenly not be emo at the end is tantamount to expecting Olberic not to act like a stalwart knight at the end.

I wouldn't say he was tricked. He tried to steal her stuff, and got punished for it. He has himself to blame for the situation he found himself in. The butler unlocked his bangle and Therion failed to either notice, or did notice it but pretended not to so as to hide his real motive for continuing to help her. His final fight isn't even a case of "I'm fighting you for revenge and because it's my job" but more "I'm trusted by others and won't let them down". He clearly fights in the end willingly for her sake, not for his freedom alone. She is the reason he begins to trust others again, then the instant he starts opening himself up, suddenly shuts himself off to the person who helped him trust others again and was the reason he saw his job to the end.