Now it's my turn mwehehehe: Laslow, Niles, Camilla, Sakura and Leo?
The only downside to some of these is that you had already told me so much about them, that I could not create a true first impression.
Laslow: I did not notice his existence at all in Birthright to be fair. I might have even killed him off while he is one of the four deaths that you can spare (sometimes this haunts me). When I started playing Conquest, I had the words of my former classmate in my head (”you’re going to like Laslow probably” and me thinking “you don’t know my taste in men!” and well here we are), so my first impression got blended in with a feeling of “well I do seem to be rather fond of this one” but it was merely attachment at that point.
Niles: I already knew he was a pervert cause of you, and honestly that was something that just ended up being confirmed. I couldn’t shape my own first impression.
Camilla: I’m going to have to dig in my memory, but I had not much of an opinion of her other than “okay she is behaving a little creepy towards Corrin” and it doesn’t help I played male Corrin most of the time.
Sakura: I was annoyed with her stuttering because I thought Fire Emblem pulled a “shy girl that stutters” anime trope. I know better now, but that was my first impression.
Leo: Of him too I could not form a true first impression, sadly.
Laslow: In the end my former classmate was right and I ended up liking the guy. Uh. A little too much, perhaps. I will always wonder how my former classmate knew as he is nothing like the other fictional character he knows I’m into. Xander may give him a lot of shit for flirting, but knowing his background as to why he flirts so much with other women, and especially with his attitude of “you never know when you see someone for the last time,” he’s simply a precious human being trying to get to know his fellow people. Over a cup of tea, if possible.
Niles: He’s still a perv, but he’s also hilarious. Not an Odin-kind of hilarious, but hilarious nonetheless. Also, he does the random meow thing like me, so I send love to this guy. Not too much love though, don’t want to give him wrong ideas.
Camilla: Strong fierce woman, do not mess with her! I still find her a bit creepy when you play male Corrin though. I don’t feel like they translated that very well. I am rather fond of her though.
Sakura: Protect her! PROTECT HER! I became rather fond of Sakura. She’s adorable.
Leo: Well… he’s… he’s a grumpy book nerd, what can I say? I did not name him Ugh Boy for nothing. I actually don’t have a strong impression of Leo, I feel like he fell a bit into the background for me.
Laslow: Gee. A favourite moment. It’s a bit rough with non-royals as light isn’t shone upon them as much (is shone proper English?). I mean, obviously I like any interaction of his with Corrin, especially when he gets serious for a moment, but uh… I cannot think of any moment other than specific supports, like the support between Laslow and Mozu.
Niles: Remember when Niles said meow? Good times. No, I actually really enjoyed the Felicia and Niles support (mostly C and B when Niles is messing around). I just love Felicia’s obliviousness towards Niles’ innuendos.
Camilla: Her fight over Corrin with Jakob, whenever Camilla threatens others showing that you can’t mess with her, her support with Elise where she tells Elise need not be like her.
Sakura: I can currently only think of her support with Kaden and Elise.
Leo: Honestly his cut scene is pretty darn cool.
Laslow: Honestly, I’m going to fall back on a headcanon post I once made. Laslow being drunk allowing Odin to mess with him as payback from the times Laslow has been reading Odin’s book as I believe Laslow would be the kind of guy to spill the beans on whatever when he’s drunk.
Niles: Niles and his daughter Nina being thieving outlaws, but for the greater good like Robin Hood, helping the poor and all that.
Camilla: I would love to see a story in which Camilla would have to be in a more realistic medieval situation where she has to be ladylike in a clean and virtuous way, especially as a royal, even though we all know that’s not who she is. Of course this story would lead to her desire to protect her family as a warrior of sorts.
Sakura: A story in (short) movie format of Elise and her having a tea party with stuffed animals would be adorable even though they are likely to be too old for that. Let the princesses be their younger selves.
Leo: Can we have a story in which Leo falls hopelessly in love with a book character? A quest to somehow turn this fictional character into something real. I’m sure Odin’s got some supportive ideas.
Laslow: Oh boy. Well, I hate Xanlow and I dislike Peri and Laslow as well, but these appear to be two of the biggest ships. I actually like Elise and Laslow, I feel that this isn’t very popular, but maybe that’s because of Elise’s age; I headcanon their relationship as innocent and pure so I guess it’s just the point of view I have. Also, I hate the very idea of Laslow in female dancer clothes because I hate how Laslow is always turned into ‘the feminine one’ in whatever gay ship they like to imagine as if gay relationships consist of ‘the masculine one’ and ‘the feminine one’, just let the characters be who they are without ‘straightening’ gay relationships. Sorry, we hit the pet peeve area as that is something that bothers me in general.
Niles: I do not think there are any unpopular opinions to be created about Niles. I think everyone loves Niles. I do am pooped he’s the only character you can have a gay relationship with, but I think everyone agrees with that.
Camilla: I don’t mind her oversexualized clothing like you said in your answer too, especially because her gear is still convincing of that it is heavy armour that is capable of protecting her. Besides, boobs are a weapon too. Do not underestimate medieval times and the ability to distract men with boobs in combat. Do not underestimate boobs. In all honesty though, I really do not mind armour showing skin so long it still looks like the armour is protecting them. That’s character design for ya. Of course it’s a typical anime trope and therefore many dislike it, but it works for Camilla.
Sakura: I do not know the opinions about Sakura cause the only person I follow reblogs Nohrians and not so much Birthright (looking at you evangeline). I cannot imagine anything I could disagree with.
Leo: The Leo and Takumi ship is something I don’t really understand, but then again, I am not far enough into Revelations yet.
Laslow: Corrin, but only my Corrin. This one’s rough. I paired him with with Elise and Azura as I liked these combinations when I play the male avatar, but I haven’t tried all things out yet (but reading into Laslow and Effie I like that Effie allows him to still chat up with women so that gets my stamp of approval as well).
Niles: I have a sincere adoration towards Niles and Felicia, I can’t help it.
Camilla: I like that putting her and Jakob together is basically a contest as to who loves Corrin more.
Sakura: Kaden!!! Sakura and Kaden are terribly adorable together! They take naps together and stuff.
Leo: I like to pair up Leo with Azura, because you forget that Leo’s a grumpy kid as he seems to enjoy Azura’s singing so much.
I just wanted to add that I am not too much of a shipper to be that invested in this section of the ask, and I simply don’t feel that strong about every character and I do not know many supports by heart.
Laslow: After the war, Laslow found that it is time to put down his sword and invests his time into what he truly loves: dancing and making people smile. He would still low-key keep himself fit for combat by implementing his skill with the sword in some of his dancing rituals in case any new war would break out or if his partner were to come to danger, but the last thing he would want for is his partner to worry for his life as he would do the same for them if they were to be sent into battle.
Niles: Despite the sadist that he is, he reveals to have a weak spot to those who seem ever so oblivious to his behaviour. He feels the need to protect these people at all costs while continuing to behave the way he is with others. No one knows this softer side of him, however, until they get close to him.
Camilla: For some reason I like to think that Camilla ends up as a cat lady, always surrounded by furry friends. And uh, don’t mess with her cats either.
Sakura: She becomes best friends with Elise. Together they would always visit peasants and offer them food and flowers whilst keeping the children entertained with toys. They are to be known the kindest princesses of their current age as they are absolutely selfless in all they do. Even whilst growing into adulthood and marrying off other men, their friendship never lost its strength.
Leo: I like to think Leo is aromantic. His love for knowledge and magic is greater than for other humans, other than the platonic love he carries for his friends and family. This is why he remains an unmarried prince and this has always worked out as Xander’s son Siegbert is to take over the throne when Xander passes. If for some reason he must marry, he would find political reasons for this much more than to marry for love.
These headcanons are not necessarily favourites, I was already happy I could come up with some whilst avoiding any headcanons that involve specific ships. Some characters already have such a strong canon that I find it hard to headcanon around it as well.