The much bigger mistake was just sitting there talking to him while knowing that she's under the effect of a spell. Should've just powered through the pain, while it was just pain compulsion instead of finalized mind control, and ran away to seek help, possibly just getting away from the mirror would be effective enough.
The thing is, she
didn't really talk to him until after the spell had already taken hold. I think the real purpose of the pain compulsion was to prevent her from running away in the first place (she was literally driven to the ground by the first "whip") and only a couple sentences passed before she succumbed to the spell.
And just overall since it was a known potential event with a side quest and everything, I don't mind it happening, it's a known character flaw and outcome. But why the fuck did Shachiku not see it coming? ... If Kiira going crazy for whatever reason is a well known major game event, then why would he not consider the outcome of Kiira's seeming anger/depression, instead of just the reason for it during their flight in this chapter?
Just seems out of character for how it's been established so far.
Well, keep in mind that from Shachiku's perspective,
everyone has been acting somewhat out-of-character and standoffish compared to the game he's familiar with. In particular, both Kiira and Daanya have been exasperated by his speedrunning shenanigans literally since day one (example:
how Kiira acted during their first meeting "irl" vs in-game), and for the little time he was aware there was an issue with Kiira at all, he was
mentally chasing a false lead and had no idea just how mad she was until she literally attacked him.
Him still being too fixated on existing game events and being unprepared for new "real game world" interactions is why it was fine before and why it's so stupid now that this has been confirmed as an existing game event, something that he should never miss in a million years, the way it's been established so far.
Now, does it absolve the writing's quality here? Not really. I think a few lines about him finding Brahms sudden retreat and Kiira's blood being practically everyone should've had him ringing some alarm bells as something to prep for, or maybe a "shit, I was so focused on other things I didn't connect the dots sooner" card could work considering what I said earlier, but either way, what's done is done, and (hopefully) the rest of this arc can help pick it back up. And, ya know, at least it's nice to read someone's critiques on this development that wasn't just letting the inherent bias about a trope clouding everything within the plot.
Yeah, genuinely a few lines like that here and there could improve it a bunch. But as it is currently, with Shachiku needing to hear a literal quote from the side quest, as if Kiira getting hostile out of nowhere isn't indication enough, it all just makes him look really slow in the head and imperceptive.
You're not necessarily wrong, but I personally think it's still to early to say. Like, that might literally be how the next chapter starts for all we currently know. And I do get the feeling that the reason it took the specific quote for him to put the pieces together is that Brams may have just inadvertently speedran the "valkyrie of misguided conviction" event; jumping straight to the finale where, in the game, there may have been a lot more setup and foreshadowing (like the trope where a party member keeps saying ominous things like "maybe we're the real villains? who can say..." and "if someone you trusted abandoned your cause, would you follow them?" for several hours of gameplay leading up to their betrayal).
I also think there's a general pattern here of Shachiku's meta knowledge and speedrunning tactics getting less and less reliable the further off the beaten path the adventure goes. Killing the demon king was basically a world record perfect run, and killing Arachne was done by-the-book as well, but Raspi not only managed to get the jump on him and bump off some characters that probably aren't even killable in-game, but also managed to cheat death (albeit getting metaphorically neutered in the process), and now Brams has gone completely off-script; I would't be surprised if, now that he knows Shachiku's secret, he starts doing things like completely abandoning his normal base just to throw him off the trail.
And I honestly think that's a good thing, narratively speaking; if Shachiku could see every twist coming all the way to the end of the series, it would lose basically all tension. (As well as the comedic potential; 99% of comedy is subverting expectations, and you can't do that by writing the same joke over and over.) I think it'll be a lot more interesting if he has to increasingly play it by ear, and so far this arc feels like a step in that direction.
