I expect that Lestilaut would have been able to use the mana absorbed by the shield too, if it hadn’t crumbled into golden dust. The whole point of black feystones is to capture mana, not to disipate it after all. Lestilaut would probably have even been able to safe the shield from being destroyed by taking out the mana Rozemyne was pouring into and casting some spells with it.

I think my only resolution to fix it is start bookworm again from p1v1, see you in a week

I think half of it is underestimating Rozemyne, but the other half is definitely that he’s got a job to do. He’s isolated without a way to communicate with his allies. It’s down to endure or die, because Cornelius will tear Grausam in half if Angelica doesn’t get there first.

In Bezewanst’s prologue chapter, where he meets with Grausam, Bindewald and Gloria, they talk about having received a letter in which Georgine heavily hinted at having discovered, how to get into the Foundation, so it could check out, that their first attempts were made, or at least planned, before the adoption, and likely frustrated by Ferdinand’s presence. Though with how little time there was between that meeting and the kidnapping attempt, I can see why they might just not have had an opportunity, before the adoption.

Or they might have prioritized getting rid of Myne, believing that this would also get rid of, or at least weaken, Ferdinand and thus make it easier to make a move on the temple in the future, once Georgine was ready to invade.

It could even be, that Bindewald was going to the temple primarily to facilitate Georgine’s taking of the Foundation, and kidnapping Myne was only the secondary objective and we just didn’t learn of it, because they didn’t take Bezewanst into their confidence. Though while I can see it being possible, I think that last option is rather unlikely. With Bindewald being interrogated with a mind-reading magic tool, chances are, Sylvester would have learned of this, had it been the case… then again, the tools aren’t infallible, especially not if Trug was involved.

Thinking about it more I’d say there was probably a word omitted. I’m thinking it was supposed to be:

On countless occasions since Georgine had discovered that Ehrenfest’s foundation was hidden within its temple, Grausam and his accomplices had attempted to sneak inside—but by then Rozemyne had been adopted by the archduke and assigned to serve as the High Bishop.

At first I wondered if the law only allowed a duchy attacked by black weapons to fight back with black weapons of their own, but not their allies… but then I remembered that Ferdinand and Eckhart are still officially Ehrenfest nobles, so any such contingency clause would apply to them…

Maybe the law against the use of black weapons against anything other than feybeasts and -plants doesn’t have any exceptions, because the Zent at the time was naive enough to assume that no large group would dare defy the law so brazenly, that the defenders wouldn’t have time to ask for permission from the royals. If that’s the case, I can see why the allied forces would be reluctant to use black weapons out in the open, at least while they still had other options. Rozemyne and Matthias would attack from within the building, so their actions would be hidden from view far more than that of the knights attacking from the air, making them far easier to hide.

As for overloading the tool: With how Grausam has already drawn absorbed mana from his arm to shoot back at the attackers, overloading it would likely be a considerable effort and risk. So it’s more of a last resort, if Rozemyne’s sneak attack fails, rather than the first go-to thing to try, I would assume. They also have to make sure they don’t completely exhaust themselves just to deal with the arm alone, or they’ll be vulnerable to any other magic tools Grausam might be carrying. To assume he came only with his prosthetic arm and two packs of Lanzenave poison would be beyond naive, especially for someone so cautious it borders on paranoia, like Ferdinand.