WARNING: The following contains spoilers for Episode 7 of Shadows House, now streaming on Funimation.
Shadows House has already established the main difference between the Nobles and the Living Dolls. It is not the fact that some of them have a face, and others spend their days locked up in their Victorian rooms, drinking tea and plotting. No, the main difference is that the Noble Shadows can control soot, the all-covering dark dust that they shed whenever they feel negative emotions, which would cover the entire mansion if the Living Dolls weren't constantly cleaning it up.
Kate, Emilico's Shadow master and the deuteragonist of the series, discovered her mastery over soot quite early into the anime when two of the stuffies that she had manipulated started to move on their own, and then to her whims. Emilico suggested that she practiced her powers, and she quickly mastered the art of moving ribbons of soot from one teapot to teacup and even using it to move Emilico around.
John, another Shadow child, could make his soot explode without it causing him any damage, although he didn't have the fine control that Kate had. However, in Episode 7, an adult Shadow showcases a terrifying power linked to Soot.
Aileen, a teen-looking Shadow who resides in the adult's wing, is seemingly in charge of communications: Whenever the other adults want to send a message to Edward, they ask her to use her powers. To do so, she conjures carrier pigeons out of soot who then fly away to meet the recipient of her message. Once they have reached their destination, their shadow beaks grow teeth and start screeching for a few seconds until they explode, leaving writing scorched on whatever surface they landed on.
Edward, who had the good sense of covering his ears while the screeching started, remarks that Aileen's pigeons always scream before exploding. Knowing how soot works creates more questions about this than it answers. For instance, we know that soot, if left alone, can coalesce into scorches, tiny bug-like creatures that will gnaw at the Living Doll's feet and are conscious. Many scorches create a Phantom, a slightly smarter and much more malicious soot monster who will try to control any human kids, usually by covering their head.
Sometimes the kid will die, poisoned by cinders and smoke, becoming a zombie-like creature. However, the more common outcome is that the Phantom perishes as soon as it comes in contact with water.
But what about the stuffies? These stuffies were made out of soot, but not the one shed and ignored by multiple generations of Nobles. But Kate's soot, specifically, was lovingly repurposed by Emilico into two adorable dolls. These stuffies are not malicious, but happy-go-lucky dolls -- as much as inanimate objects can have a personality. This suggests that soot creatures can acquire consciousness, and their overall wants and experiences depend on the circumstances of their creation.
This brings us back to Episode 7's Aileen, who is basically making sentient soot animals just to send them to an explosive death, only to spare the adult shadows a stroll down the gardens. From this perspective, her pigeon wasn't screeching because the Shadows dislike Edward, but because it knew that it was going to die in a matter of seconds; it was expressing its horror, not trying to convey a message through its last desperate tweets.
This also leads to the next logical conclusion: The Shadows themselves are made of soot -- so, could they be an artificial conceit created by an even more powerful Noble? And if so, is this creature using them in a cruel game, just like Aileen uses her pigeons and like some of the Noble Children abuse their Living Dolls? After all, John Noble's explosion was very similar to that of the pigeon. The Shadow Children, therefore, can't be sure that someone won't let them die just because it's convenient.
Shadows House, based on the manga by Somato, was created by CloverWorks, directed by Kazuki Ōhashi, written by Toshiya Ōno, with character design by Chizuko Kusakabe and music by Kenichiro Suehiro and is currently streaming on Funimation.