Not really spoilers but

Since many are only manga readers, I come with some extra info from the novel that you've of course missed! Don't worry it's not spoilers, as it's Ursch's POV from way back (probably around the first or second novel chapters which are the first two manga chapters here I believe) and the now released chapter 7! Just hoping it helps someone who doesn't necessarily wants to read the novel :)

First of all, the novel tags include YANDERE ML. Many wonder if Ursch is a yandere character or not but at least the tags in novelupdates include that one so yes he is confirmed as one so far.

Second of all, HE LOVES ISABELLA. I know that many are worried that because he's a yandere or whatnot Isabella won't be happy and such (I understand why you'd be worried, she deserves the world) but that's why I come with this info here:

In Ursch's POV, which you see a little of in the manga (when he explains about 'his treasure' and how he's found it) you can truly feel how much he loves and cares for Isabella. He would never hurt her or do anything that would make her unhappy, so don't worry about that. He has a LONG speech, it's a full extra chapter yes, explaining the whole treasure thing better and why he's fallen hard for such a cute girl and else. It's honestly adorable, not creepy nor scary at all.
Second of all, Isabella hints in the novel that she KNOWS about Ursch's yandere tendencies and vibes while getting to know him, and she doesn't care. In fact, she's happy that she's getting to know him better and just like the latest manga showed she's willing to stay with him forever even after knowing his scary side.
Chapter 7 and 8 of the manga cover the, so far, longest novel chapter, and of course a lot has been missing (specially their inner thoughts). When Ursch says that even if she's sick of him and tries to run away he won't leave her side, Isabella has a small inner speech talking about how his personality is truly different from what she thought and recalls a lot of incidents that have happened since they met. She clearly states, like I mentioned previously, that she loves him all the same and is actually happy he would feel so possessive of her which is why she replies the way she does. Isabella is not a yandere of course, but damn she's pretty obsessed in a healthier way I guess? of Ursch as well so you could say they're the perfect couple!!! It's honestly quite endearing if anything.

Hope this gave more intel to those who wish for it, I just love this series very much (๑•ㅂ•)و✧