Regressor!Howl Headcanons
Now, Howl couldn't exactly say when it was that he started regressing—his headspace has always been very fluid, and it's not exactly like he felt the need to mark the date or note the event that triggered his regression for the first time. Because like with much of his life, it sort of just happened upon him, simultaneously ordinary and yet utterly remarkable as a great many things are. But what he can (and will!) say is that he is a big kid! Most of the time he averages about six or seven years old when he is regressed, but he will slide on down to a precocious four should certain conditions be met and the stars align just so—if you count things like missing lunch because he was too busy playing and getting hangry as a result as the stars aligning, that is. Though this tendency to slip to a lower four is something that he is in a bit of denial about, and if asked how old he is he will answer that he's seven regardless of whether or not that is strictly true at the moment. And he is seven!...sometimes, at least. So it isn't technically a lie, is it? What matters to Howl is that he can maintain his lifestyle of remaining free and unhindered; he's a big boy who can take care of himself, so he doesn't need anyone telling him what to do.
As such, being the the independent big kid that he believed himself to be, he didn't really seek out a caregiver. That is until Sophie came along. She inserted herself seamlessly into his life, and so the fact that she started minding after him more than she probably would otherwise went unnoticed at first. She was making sure he ate regularly, cleaning up his messes that spanned the entire castle, and checking on him even when nobody had asked her. Mostly because something told her he needed someone to mind after him; it isn't until later when she catches him playing with Markl that she makes the connection that perhaps she feels that way because it's something that Howl needs. She watches to be certain, noting how they play together more like peers than like a master entertaining his young apprentice—or maybe not quite peers, as it appears Markl redirects a fussy Howl without even noticing, reminding him that he has to play fair when it seems the boy tries to make up new rules on the spot to suit his needs—and decides to test the waters a little by treating them more similarly for the rest of the afternoon. Much to Sophie's surprise he responds well to the subtle changes in her doting on him. But none are as surprised as Howl himself, because he finds that he actually likes having someone take care of him.
Howl has a tendency to tell tall-tales when he's small, exaggerating every small detail until he's left with something truly fantastical. It isn't necessarily harmful per se—after all, it does show a certain degree of creativity, and he isn't exactly lying about anything that could result in someone getting hurt. But it is a habit that Sophie would like to redirect in some way, given that a large part of this appears to stem from how he perceives himself battling with the way he wishes to be perceived by others. And while his recounting of his many escapades fall victim to this, it's a rather small lie that truly worries Sophie. One that she catches him in early on in fact when she asks him about his regression to try and find out if he's comfortable with her helping him while he's feeling small. A defensively huffed all wizards regress is the near-immediate answer, the way insistence of the "fact" bleeds into a desperation as if begging her to believe him definitely creates a spike of concern in her chest. While not outright correcting him (as it would only cause him a lot of distress), Sophie makes sure that she works with him so that he learns that not everybody regresses, and that it is okay that he does—it doesn't make him any less Howl, if anything it makes him more Howl.
Whether or not small Howl picks up on Sophie's desire to help him is unclear, but what is clear is that small Howl wants to be Sophie's little helper. Wants to help her so so badly, all in an effort to impress her. Sophie does everything! She's amazing and he loves her so much! Surely he can help. Though as it turns out it would be more apt to call him her little troublemaker, given that he often winds up underfoot and accidentally makes extra work for her instead. It isn't as if Howl means to of course, he is just a very involved kid that gets into everything he possibly can. But she doesn't really mind it much, knowing he means well; she often will come up with little tasks specifically for Howl to both keep him occupied and make her job as his cg run a bit more smoothly. Moreover, Sophie often feels that it is the opposite way around and that she is a toddler's assistant—running behind him and picking up his messes, telling him when it's time for a nap, fixing him his lunch (and making sure he actually eats it), helping him manage those big emotions.
On the topic of big emotions, Howl can be a little bit fussy at times. He's very particular about things being a certain way and can get haughty as a result. Things should go his way, they are always better if they go his way! Or so he believes. The little huff-puffs he gives are the first warning sign of a tantrum being imminent, followed either by frustrated tears or an utter shutdown as his emotions overtake him. Both options are a bit not good, though the former sees him remaining verbal and not completely despondent. Before meeting her, he would just have to let the meltdowns run their course and ride it out on his own. With Sophie entering his life however, she seemingly knows exactly how to diffuse the situation and begin to bring him back down to a calmer state. It's during this time that he hits that lower end of his age range, and so Howl only whines a little about how he can take care of himself as she gets him a quick bath and then settled in bed with his stuffies, too tired and worn out from his emotional outburst to keep up his usual high energy. It's easier to let Sophie guide him down and into dreamland than to let his upset keep its vice grip on him, her guidance a reprieve from how unsure his emotions can make him feel.
Although Sophie tends to be more lenient (extremely lenient, some Calcifer might say), there are definitely times where she takes a firmer approach with him, usually out of concern for his own safety. This typically occurs when, ever convinced of his maturity and confident in his abilities, Howl decides to use his magic while he's small. Most of the time it's only small spells, things only meant to entertain himself and Markl, like changing the colors or sizes of things. But there are others times as well, times when he attempts to use forms of magic that really should be reserved for his big self only. It is a dangerous thing when a seven-year-old gets a wild hair and decides to move the entire castle on a whim and make it to where one of the doorways open up next to an ice-cream shop. There's a lot of chaos when this happens, everything shaking as a child's unrefined magic makes the necessary spatial transition coupled with the gleeful laughter from a far too pleased Howl as it works. But before he can run out the door and acquire the coveted ice-cream cone that he pulled this little stunt for, Sophie has grabbed him by his collar and is giving him a good scolding. He could have gotten himself hurt, could have gotten them all hurt, why didn't he wait or get help if he really wanted to move the castle that badly? However Howl genuinely doesn't understand why doing magic when he's regressed isn't necessarily a good idea, and so the scolding earns her a hiccupy little guy that promises he won't do it again. (He immediately forgets this promise and will do it again, but it's the thought that counts!)
Even with Sophie picking up after him, the castle can, at best, be described as cluttercore. This kid has collections, collections upon collections even with everything arranged just so, believe it or not. The cluttercore nature of the castle however lends rather well to a certain game: hide-and-seek. According to Howl this is the best game to play, and Markl seems to agree—games of hide-and-seek can last for hours if they play in the castle, but especially if they include the areas outside the castle as well. Though Sophie has asked that they stop hiding in the towns where they have their storefronts set up, this perhaps leads to her inclusion in their game; with her being a something of a worrier, she tends to act as their seeker most days. It allows her to keep an eye on Howl (with a little help from Calcifer, of course, who is more than willing to help point her in the right direction when he can if it means keeping Howl in check). Plus, it allows Howl to be a hider! While he is a strong proponent of the game being The Best EverTM, Howl only wants to play if he can hide! It isn't fun having to be the seeker for him since he gets so easily frustrated. He gets so stompy if he has to be the seeker and whines that his talents as a hider are being wasted.