Re: question
Him being a cat lady is basically the most amazing thing in the world, tbh. I know that feel, bro.
Arthur is... really, really confused about it all. Since their confrontation and hearing from others, he's learned that the blizzard itself was Elsa's doing - but that it's likely that she hadn't meant for it to happen? He wants to believe that's the case for blasting Merlin (and others) with the ice magic... but considering their conversation, he's wary since Elsa said some sketchy things (as he interpreted it) and he's still smarting from practically begging her to save Merlin and her refusing (taking that as refusal rather than, well, her being incapable of doing so).
Arthur places his trust implicitly in people all the time - he always believes the best in others and always just trusts in them even when others would obviously be wary after being betrayed so many times in his life (like seriously, everyone he's been close to has betrayed him at one point or another). So he's viewing this again as another "I trusted someone I shouldn't have" because up until this blizzard thing, he thought that he and Elsa at least understood each other a little, or, at least, they were on quasi-friendly terms, despite Elsa's reservations.
So he's kind of having a "well, should I have expected this?" moment, and blames himself for some kind of past error he must have made - since now it's clear Elsa has magic, and he wonders if he said something thoughtless or hurtful to her in regards to magic, and thus betrayed her trust first.
And to be predictable, Elsa's thoughts on Arthur at the moment?