Author's notes and observations
1. Demon genes are weird. How could one brother be half-demon while the other pure-blood when they both share the same mother even if not the same father?
2. In Heroes of Maple, Damien commands an army of half-demons, which begs the question of where did they all come from? Considering that the demons believe that strong have the right over the weak, is it so farfetched to imagine that defenseless humans were kidnapped or even raped by them? Fridge horror.
3. For all intents and purposes, I find it hard to believe that this family is living alone in the middle of Minar in anything other than poverty. How would they have gotten the basic essentials of, if not food and water, then clothes, tools, soap, and other necessities? How would they afford it?
4. DS mentioned that he joined the Black Mage for his aims. At first I was ? because what aims? The Black Mage was created by Maple to be evil because evil. He had no true character, much less goals. I was stuck on this for a while and if not for this point, I would've published this story in October. But then as I was replaying the last segment of Zero's story when the Commanders tried to recruit Alpha and Beta on Youtube, I remembered the Black Mage wanted something to do with combining the worlds. All that was left was for me to brainstorm why DS would be on board with that. Of course, it would be for his family's sake. No other reason but his family could ever make him leave them, not when his love for them was strong enough that he would betray the Black Mage and seek vengeance even after.
5. There was a major misalignment with what happened to Damien after he accidentally destroyed the house. On one hand, Arkarium took him in, but on the other, he was somehow exiled with the other half-demons to Tynerum? Which one is it? So what I settled on after some thinking was that Arkarium was initially going to take Damien back with him but decided he needed to suffer for a while longer and saved him only to drop him off in the middle of nowhere to writhe in agony over what he thought he did.
6. I'm dying of heartbreak someone he lp m e.
Regarding Demon Slayer's reasons for joining Black Mage:
[Originally posted on AO3 as an answer to a comment]
In my story, DS touched upon the reason I thought would fit him best but left it intentionally vague because it's a line of question that DS has thought about for a long time and thus has some logical leaps as well as some context I didn't add into the story for the sake of simplicity and so the story could focus on the eponymous red scarf symbolizing Damien's bond with DS so here's his reason if you want to read it:
In the time DS and Damien lived in, many half-demons sought shelter in Maple World to escape from pure-blooded tyranny. Under Aria's rule, they are welcome, but the citizens are less trustful because they're aware that pure-blooded demons (who sometimes manage to slip by into Maple) were known to kidnap humans and rape them. They're wary and thus there's a certain tension. Half-demons ended up creating settlements where they could live in peace with those in similar situations. But DS is worried that Aria's hand is too gentle to stop discrimination or to keep equality between humans and demons. DS also determines that Aria is mortal, just like his mother, and when she died, what would become of him and his brother? In their longevity, three generations of rulers would pass quickly and there will eventually be one ruler who finally banishes them back into Tynerum.
However, what if there's a ruler who could live just as long if not even longer than them? But even if there is such a ruler, it doesn't get to the heart of the problem, which is inequality, whether it be between pure-bloods and half-demons or half-demons and humans. As long as it exists, future banishment to Tynerum and his brother's endangerment in that land is always a possibility. Black Mage's idea of one world under his rule appealed to him because not only does he have the longevity, but DS hopes that under the Black Mage's rule, he'll be able to crush inequality under his hand even if it's with pure strength. Everyone'll have to listen to him, even the pure-bloods. DS is a bit saddened that everything goes back to relying on violence and strength yet again (his blood is something he's always being troubled about but that's another thing) but he sees this as the best future in the long-term for him and especially Damien.