Head canon: Harrow has some elvish blood/ancestry. Explains why his biological son can talk to animals (which really seems like an earth-blood elf thing), why Harrow knows about Aaravos/his cube, and why Harrow has some idea of Callum’s destiny as a mage. Especially while Viren, the court mage, knows NOTHING about Aaravos. (At least at the start of the series.) Callum meanwhile is still 100% human.
Hmm, that could be an interesting theory! It would explain a great many things, and would be a reasonable outcome to whatever story “The Orphan Queen” (which I think will ultimately explain where the Rune Cube came from and how it wound up in Harrow’s family).
You’re also right that it’s a good way to explain how it is Harrow knew so much so early on--Aaravos, the Rune Cube, its legend, Callum having “great things” inside him that require both the sketchbook and the Cube. If there is something in his heritage that explains all of this, that would make a whole lot of sense!
I’m usually really hesitant to explain humans doing magical things as due to some elven ancestry, since that detracts from what of the main themes of the story here, which is that humans have a greater potential with magic than anyone had initially realized. But with Ezran and Harrow, them being able to do magic would be a mystery in any circumstance anyway, so making their abilities being due to elven ancestry would make sense.
However, the problem I usually run into with Ezran’s ability to talk to animals is that, if this is an Earth Arcanum thing, then why doesn’t the cube light up when it touches him? I’d be pretty surprised if, as soon as Callum realized his brother can actually talk to animals, he doesn’t just take out the Rune Cube and go “wait lemme see something.”
Hearing the way Ezran describes it (in Callum’s Spellbook), his way of learning to communicate with animals sounds an awful lot like how Callum learns the Sky Arcanum; he just gets a feel for what they are feeling, and then it eventually came together.
But then again, how it is that Ezran did all of this without setting off the Rune Cube, I have no idea. It’s possible his abilities are something very different from Dark and Primal Magic.
We’ll probably be learning more about his powers soon enough. And I’m looking forward to more of this magic munchkin!














