Replacing Draco Malfoy with the "Malfoid", Draecina sends ripples through the whole edifice that Rowling built.
It's how stories grow.
Build one corner, and that corner makes you ask the questions that help you build another.
If you replace a cardstock bully with a prideful and complex debutante, who yearns for forbidden things, and must eventually choose between her family, her heritage, her entire world, and the boy she loves, then this fills out the next part of the story by making us ask "why?"
Why does she fall in love with Harry Potter?
That answer depends on what she wants. And what she wants depends on where she comes from.
And both these questions ultimately wind up at her father. Because a little girl learns about men, and about love, from her father.
Now, it would be easy to declare that Lucius Malfoy is to be a cold, vicious, domineering, hypocritical, selfish, and abusive man.
And therefore loving Harry Potter becomes an act of defiance. Becomes that tired old trope of kissing the motorcycle hoodlum to piss off daddy.
But that's not love. That's daddy issues. And daddy issues will not change a girl. They will not carry her though the fire. They will not make her a hero.
We can do better than that.
Try the opposite. Lucius Malfoy's creed and values, repugnant though they are to our original author, are deeply and sincerely held. He does not believe in elites merely because he wishes to be one of them.
He believes that the gifted, the talented, the blessed, are needed by the world, and their privileges come with a price of responsibility.
So he has raised both his children with love, holding back nothing that it was in his power to give. But he has raised them for a mission in life, and never made his expectations anything less than clear.
Draecina is to spend her childhood and teenage years preparing herself to lead. And she is to marry wisely, to preserve and improve a bloodline that is precious to the world.
Now we know both why she falls in love with Harry Potter, and why she is terrified to admit this, first to herself, then to others.
Harry Potter, you see, has all the traits of an attractive boy, courage, competence, athleticism, popularity, the respect of children and adults alike. He is always the main character, and a heroic one at that.
But he is also a rogue. A scamp. A mischief maker. He does not do as he is told. He acts of his own accord. And in so doing, he always seems to end up saving the day, to wild applause.
How could she not admire him? How could she not yearn to be part of his little band of troublemakers, sneaking about at night and breaking the rules?
And when she is just a bit older, with early puberty bringing on thoughts of boys, how can he not represent the one thing she has been told she must not have, as the price of all her privilege?
Passion.
She doesn't want to sit in a parlour, silent save for a loudly ticking clock, and make awkward conversation with a series of well-bred boys who have been ushered into her presence for the sake of their race-horse bloodlines.
She wants to feel. She wants to run barefoot in the rain. She wants the school's handsome and popular rogue to kiss her and tangle his fingers in her hair.
But she is terrified.
Too terrified to admit her feelings even to herself. And when she cannot avoid that, too terrified to act on them, hiding away from the boy she desperately yearns to follow after, pushing him away with words of scorn so that no one will suspect, then seeking him out only to fight with him, because if they are fighting, then at least he is looking at her, and anything is better than his absence.
Why is she terrified? Of what? Of who?
Of her father.
Not of his scorn. Not of punishment. Not of his hard hands, for he has never struck her and never would. He has never shown her anything but love.
And this is the cruelest trap of all.
She is terrified of disappointing him. Daddy's girl cannot bear the thought of losing his love. He can never know who she has chosen to love, because then his patient, quiet disappointment would force her to choose.
And she cannot.
Every day she is tortured by guilt. She is a Bad Girl. She has been given everything, had every advantage, and still she cannot put her heart into the small measure of responsibility that the world asks in return.
But while she cannot bear to choose Harry Potter over her family, or her family over Harry Potter, her choice is already made, and it is inevitable, because she has chosen him over any suitor that their quiet, thoughtful calculations of bloodline and political advantage could ever bring to her door.
This is why she taunts him for his "low-class" behavior, and seeks to part him from "the wrong kind of friends". Because she harbors the fantasy, impossible though it is, that he, Harry Potter, the boy who holds her heart, can somehow become, be accepted as, one of the elites, as defined in the rules of her world.
It's impossible, of course. He's a half-blood. Sure, he has power and skill in his own right, even fame, but for a child of the Malfoys? Never.
So she yearns for him, succumbing sometimes to temptation and pulling him near, only to drive him away again as she is wracked by guilt and shame.
She cannot choose him, cannot commit to her love for him, until she begins to see that her father, following his beliefs, has made reckless choices with dire consequences.
Until she begins to think the unthinkable... that her father, the lordly, infalible Lucius Malfoy, might be wrong.
Oh, not wrong that some people are better than others. She believes she is one of the elite, deserving of privilege, and she will believe this to her dying day.
No, her father is not wrong about the order of the world. He is merely wrong about how those elites are to be discovered and known.
Harry Potter, in the final dark days before the war, has shown his nobility. He is one of the elite, whether her father can see it or not.
That is the moment she can say, in the privacy of her own head, I love him. I love him, and the question is not, was never, whether he is worthy of me.
But whether I was worthy of him.
She does not know. But she must try. She must run to his side, to stand with him, fight beside him, to add her strength to his in the hour of greatest need.
To declare to the world that she chooses him, to declare it even without knowing, in that moment, if he will choose her in return.
A leap of faith.
Because she has loved him, but up to this moment, she has loved him selfishly, making her feelings of love, of being in love, more important than him.
So now she must declare what she hid, without protecting herself, heedless of risk.
It is not sacrifice itself, but choice to sacrifice, willingness to sacrifice, that calls the power down.
(That's how I'd write it, anyway.)