The constraint is always raw material. She has no shortage of ideas or time in which to put them into practice. Hence, she is most avaricious in acquiring hearts whenever an opportunity presents itself. Having a stockpile means she need waste as little time as possible.
The people of this village - one of the larger ones humans have attempted so close to a fairy city - would quite object to that. Several of them seem quite adept at heartful magic -
Though of course no match for her artifacts.
Their objections are of no concern, of course. Simple annoyances to be swatted out of her way that she might carry on uninterrupted.
- Someone walks into the village.
He's vibrant, colors settled into him with more life than they do for most humans. His hair is a gleaming white, his robes a blue like sapphires, the black of his fur trim so utterly black it might be best to call all other shades of that color a light grey. His eyes are green, glittering with shards of gold and blue, and his staff of ivory is topped with a gem that sparkles with a marvelous iridescence.
He doesn't seem at all concerned with the fairy's power, and his magic lashes out in a rainbow of color, shielding the people as they flee, restoring color to those who have lost their hearts to her but not yet died.
"This is not," he grumbles, "Proper behavior."
"You don't understand the true value of a heart, do you? To you they're just toys, raw materials - "
"Obviously. If you are going to continue to be bothersome, old man, I will take my leave."
He taps his staff on the ground.
"You will understand."
And color washes over the plaza - washes over her, kindling something in her chest...
"Even one such as you may have a heart," he says, voice ominous, and then vanishes in a swirl of color.
The humans are gone, too.
She's angry.
She's angry at that man. He's gone but she's still angry. How dare he do this to her? Take her artifacts, take her prey. How dare he. He will pay for this. She will make him pay. Hunt him down and feed his face to the dogs.
She needs to figure out how to find him. Can't use any of her artifacts because of this useless lump in chest. Fuck that old man. She doesn't really want to go back to the city like this.
So.
The Heartful have magic. She should figure out how to use it. Scavenge what she can here and then... push outward.
There's food, some of it already prepared so it'll keep for the winter. There's clothes, in sensible colors (her own outfit, once no longer in the grey-scale of the Heartless, is quite colorful apparently). There's tools and bags and daily usable stuff - none of it artifacts. There's no books, nor any indication of writing.
What a pain. Don't humans know how to read?
She'll trade out her outfit for a darker one. Pick a pair of bags and fill them with a collection of food and useful items. No maps or anything at all?
There's crude maps of their fields - on wood, not paper - with little symbols of different plants. No larger scale maps, though.
Idiot humans with their idiot hearts. Whatever.
One direction's as good as another, then. She starts walking.
There's trails, cut through the forest. This one winds down-slope, towards and then over a peaceful stream, until there's a rhythmic ting! ting ting! ting! sound curling through the trees as they start to thin out.
That sound is intensely annoying. She would very much like to kill whoever's making it.
Seems to be: a blacksmith! Working in a smithy a distance from another, smaller village. He stops when Shade comes into sight, smiling a bit, and calls out, "Hello and well met, stranger! Are you from down Luta's way?"
"Village up the hill? Paths might be a bit different than I remember, I 'spose, haven't been that way in a while."
"Of the area? Think there's one with the priests, since they do the coordinating trails and all."