That's not how matrilineal marriages work. All it means is that the children the couple would have together would take the mother's family name and would be considered part of that noble house rather than the father. It doesn't mean the father would have to give up any titles or holdings they'd already had or that any children they had before hand or afterwards with different woman would join as well. Only his children with Sarah would be part of Sarah's household in an actual matrilineal marriage.
his other engagements weren't matrilineal,they joined his family so they fall under his house,doing a matrilineal marriage after that would mean his family(which would include Karla & avila at that point) they to fall under Sarah's family,which would mean the Queen being their head off house would have the final say on matters.
that would included his other children,although yes they are not blood related they would be still be under their father,who in turn would be under the queen.(they'd be some kinda branch or bastard)
the MC would absolutely have to give up any title's or holdings if ordered to do so legally speaking.(not only because she's queen thus his liedge but doubly so with the head house on top)
If he's a "toy" then he'd be a toy to the Queen in that situation not to the princess. And he's still a toy then since. But Sarah isn't strong enough to force him to actually do something he doesn't want to do.
Yeah again nobody can make him physically do something. It doesn't matter if they're the "head of the household" that's not the same as being a sex slave. You have a really weird view of marriage if you think being the head of the house means your spouse has to blindly follow what you say no questions asked. Like I said it's marriage not slavery. The mc's objection really comes off more like an ego thing than anything actually sensible.
you're not wrong about it being a ego thing,in that situation he can legally refuse the marriage because he is a mage (thus is granted a lower noble title off knight which grants "marriage rights) which he did because he doesn't want to not be his own head of house in the future.
which i don't think is a bad thing perse.
and they can't force him?
well...let's say he did accept and married her,now the Queen(whom likely would still be under the demons influence because his refusal caused them to discover her) could order him to also marry others,use his money and other assets as they see fit.
sure he could kick & scream but if he doesn't do it/let it happen,then the queen is in her legal right to disown or brand him a criminal (which is a literal thing which could involve magical slavery and being forced to do things regardless of will)
it seems to me you're doing two things:
1.you're confusing the norms & laws off this fictional setting with IRL
2.being hypocritical because you don't like it when he's objecting/resist/rebelling against the marriage,because he could just do it when is actually married(which is where he'd have a lot more consequences)
Yes, and that's not at all how that worked in a feudal society.
that's a very meme way off how it worked ,and still works.
Force doctrine,don't think so? don't pay your taxes and see what happens....