YIPPEEEEE YAHOOO YOU'RE BACK oh my god we need Casphardt more than ever in these trying times..... say... would you mind sharing some assorted headcanons about the two of them?
*RUBS MY GAY LIL HANDS TOGETHER* HEADCANONS, YOU SAY?
Oh I am SO glad to be back, because I've had so many headcanons about these two stored in my head for YEARS.
They just Know what the other means. They've been around each other so long that the way they communicate with each other is cryptic to most but makes complete sense to them. Caspar can tell when Linhardt is actually frustrated and annoyed by someone (even himself), vs just feigning it. Linhardt can tell when Caspar's smiles are forced and when he's actually hiding his (physical and emotional) pain.
Linhardt completely avoids calling Caspar stupid. Canonically, he's never implied that Caspar is unintelligent, nor does he ever act like he is (this is something I see in fics a lot and I think it's a vast mischaracterization of Linhardt's character). The headcanon part is that he avoids calling Caspar stupid because Caspar's heard it too many times from others, to the point where he actually believes it himself (see his Hopes support with Ferdinand), because to Linhardt, it shows that people do not understand him. If Caspar ever called himself stupid around Linhardt, Linhardt would be the first one to tell him that he is not.
They are the embodiment of both wearing "I Get Us Into Trouble" shirts. Caspar often involves himself in fights he has no business involving himself in, and Linhardt loves accessing forbidden areas he has no business being in. This makes their post-war adventures extra chaotic.
Caspar is a kinesthetic learner. He learns by doing and needs hands-on experience. Linhardt is of course a reading/writing learner. He learns by reading and making notes. That said, Caspar is surprisingly good at picking up cooking when he learns alongside someone teaching him, or if you subscribe to the non-CF headcanon, did a LOT of trial and error cooking when he was on his own (by pure necessity of survival). His cooking is atrocious if you try to get him to make anything for the first time, but gets better with subsequent attempts. Linhardt, on the other hand, NEEDS a recipe or he will not even bother.
Related to the above, the two pick up some small bit of different languages in their adventures after the war. Caspar, being very social, picks up on greetings and phrases, and knows how to repeat them after enough exposure to it. Linhardt picks them up through reading signs and books, and carrying a personal dictionary around that he himself makes notes in.
They get married in every new country they visit. They have proposed to each other several times.
Linhardt gets seasick. First time he learns this is on their trip to Brigid.
They each have their ways of calming the other down when it comes to their respective phobias.
As kids, Caspar was actually the taller one. Once they hit puberty, Linhardt's growth spurt overtook him and Caspar ended up being a late bloomer.
They're both neurodivergent in opposite directions with a lot of overlap. Caspar's hyperactive ADHD and Linhardt's inattentive AuDHD are one of the things among many that made them able to understand each other better than most.
Neither of them actually remember the day they met, because as far as they're concerned, they've always been in each other's lives. But they remember so many other things from their childhood, including how they decided they were best friends.
As they get older when they settle down in their cottage, Caspar's memory gets worse while Linhardt ends up needing reading glasses and walking assistance. Caspar loves telling stories about their adventures to kids, but Linhardt ends up needing to correct him on a lot of it. But Caspar never forgets his most important memories with Linhardt.
When they settle down, Caspar gets into smithing and woodworking (mainly for tools made for hunting, building, and repair. He also built a lot of their furniture!), and Linhardt runs a small clinic for the nearby village. They don't live in the village themselves, but a short walking distance from it. The quiet is nice for both of them while not being too far from civilization.
They end up living somewhere in Leicester territory.
I know I have more, but they're not coming up in my head atm. But these are the first ones that immediately come to mind. :)