Sooooo...y'all think Charlotte and Luck are siblings? It's something that's been in consideration since the elf possession happened and they got taken over by elves who are siblings (Charla and Rufel).
Here's what supports the idea, as far as I can tell:
1. As said above, their elf counterparts were siblings, with Rufel being the little brother Charla talked about wanting to see while she was around.
2. Luck doesn't know his father. He lived alone with his mother.
3. Luck has magic on the level of a noble, despite being a commoner.
4. Luck and Charlotte both have blonde hair and blue eyes.
5. Luck's grimoire has plants on it.
These are what lend credence to the idea afaik.
#4 is not super convincing because Luck's mother has blonde hair and blue eyes so he'd have just gotten it from her but it's still interesting cause as of now, I'm fairly certain they're the only two alive characters in the series with both traits, which does link them in a way (basically, it's not good enough on its own but interesting when taking the rest into account).
The most interesting one, after their elf counterparts, is Luck's grimoire having plants as part of its design cause I don't really see a reason for that to be there. Could be seen as just some random flourishes but again, it becomes more interesting when taken with the other points (reminder: Charlotte is from House
Roselei). And we have had grimoires hint at future developments before, like with Charmy's grimoire having a knife and fork on it long before she was shown to have "Food Magic" as her second attribute, with her wolf literally using those utensils.
If Luck was somehow the illegitimate son of F-Roselei, it'd add another layer to his mother's joy at him winning against a noble as a kid. I don't see how this would come up and/or be revealed if it's true but maybe if we learn more about who cursed Charlotte and why they did, it'll somehow tie into it.
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A potential big flaw in the idea is that elf-possession shouldn't be an indication of folks being half-siblings because Finral didn't get possessed like Langris. Which is fair but actually ties into another small interesting theory, the idea that Finral actually was meant to be possessed (which if true, would then not be able to disprove the Luck/Char idea).
This is a simple one really. Here's child Latry (who possessed Langris) playing with Patry (first-person perspective flashback) and an elf who might be Finral's counterpart. I say that because of who he's with and because his hair is similar to Finral's initial hairstyle without the bangs in the middle.
(the hairstyle also looks similar to this
guy but I don't think that's his elf again because of the company he's in and also because the anime showed him to be closer in age to Licht, while those are children)
So if that's supposed to be Finral's elf, why wouldn't Finral have gotten possessed?
(Edit: Btw the first appearance of "True Magic" tier, which wouldn't be seen again until Gaja showed up. Maybe we'll see more this arc.)
Because Rades messed things up and 3 souls that were meant to be sacrificed were not. Patry's plan to sacrifice the Midnight Sun members he marked clearly wasn't an all-or-nothing thing given all the reincarnations that did happen despite Rades' spell, yet he did mark Rades, Sally and Valtos, so it likely was "1 human soul sacrificed = 1 elf soul reincarnated" and Rades prevented 3 souls from being sacrificed. So Finral was possibly spared from possession due to this (maybe random luck, maybe because he was still asleep/incapacitated and the reincarnation prioritized able targets).
Which, to go back to the initial point, is why this wouldn't disprove the Luck/Charla thing imo. (Doubt this second one would ever get confirmed though)
Soooo...are Luck/Charlotte siblings?