Thanks for translating!
The French invasion of Russia, colorised. Honestly there's a lot of selfish, idiotic people in this chapter. The Crown Prince is going to REALLY regret asking Yustaf about her, and the invading lord will live to regret attacking them. I hope that she invades him in turn, and claims his mines for herself. They could make their own monopoly on the crystals fairly easily. The emperor may be the dumbest of them all though. The Duchy and its line have been holding back whatever the hell is behind that door for centuries, and he sold them off to invaders. Secretly giving him permission to invade is practically declaring war on the Duchy yourself, and now the most powerful area of your kingdom has gone from an ally to an enemy. If our MC is smart she can majorly push back against the Emperor over this. If she really wanted to push her luck she could stop paying taxes entirely and dare him to challenge her about it, any attempt to outright attack the Duchy would almost certainly devolve into a civil war. And with their mage disabling stones, that fight could turn nasty very quickly.