Could you please write some yandere headcanons for Captain from Hellsing, Alucard from Hellsing, and Reiner from Aot in a scenario where they save darling from a dangerous situation such as maybe being taken hostage or just in a near death experience. And afterwards let a scared, teary eyed darling go to them willingly for comfort for the first time since being kidnapped by the yandere. Maybe even let Darling give them a hesitant kiss on the cheek in thanks.
The Captain's normally not that expressive, but the instant his mate's in danger he's seeing red and will immediately kill whoever's put them in danger. It's not even something he thinks about, that's just his instinctive reaction once he sees them or hears them scream.
Once the danger is over he'd ignore their crying or shaking and silently check them over for any injuries; once he deems that they're fine, he plans on dragging them back to his quarters. Normally they resist a little when he takes them by the arm or puts them over his shoulder, but this time they actually take his arm in theirs. Hell, they're clinging to him. It's...odd. Not unpleasant, but he's not used to affection. This could legitimately be the first time he's received it. Like. Ever
Once he's locked the door he expects them to let go, but instead they move to wrap both their arms around him. They're crying a little, which he's used to, but they're thanking him. Unfortunately the blood still covering his clothes is now on them (well, not unfortunate for him--he doesn't mind, but they seem to be averse to blood. Humans are strange and delicate like that, since they're prey animals). So to try and return the affection they've given him, he just takes their hands and licks the blood off before doing the same to their cheek. It's strange not feeling them flinch when he's this close. And what's even stranger is when they do something similar to him; not a lick or a bite, but just putting their lips on his cheek for a moment.
He pauses and imitates the action, only putting his lips on the spot he'd just cleaned blood off. They don't stop him, so he sits them down on his bed and keeps doing it in different spots along their face, neck, and hands. The adrenaline from what happened to them must've worn off because soon they're falling asleep against him, and he enjoys watching them for a while.
Alucard can take out most threats instantly, but he still feels this ever so slight sense of alarm and worry the moment before he kills any and every creature that had Darling in their clutches. There's no mad grinning or sense of amusement when he kills and devours this time, it's just a very cold rage. He lets them know that his hound is going to chew them up and shit them out, but apart from that he says very little.
Once they're dealt with, he's back to normal though. He'll ask if they're ready to come back home, and when he sees they're shaking he just smirks. They really are his little Rabbit. He's used to seeing them anxious, terrified even, but usually they either pull away from him or go limp...or if they're feeling feisty, like they did in the beginning, they'd try to fight or kill him.
Which is why he doesn't expect it when they grab onto him and bury their face in his chest. Warmth is something he can only experience from others and the world around him, but Darling wrapping themselves around him like this almost feels like he's warm-blooded and human. Almost.
He picks them up easily and happily lets them cling to him, but he actually hesitates if they kiss him. He loves that they're being so forward and affectionate, but he knows that this is likely just them being grateful for his rescue and needing an outlet for the terror that's got their heartbeat pounding in his ears. He'd rather wait until they come to him completely willingly to take things further. That said, he doesn't tell them to stop either, and he's happy to caress and hold them while they curl up against him.
Reiner's the kind of yandere that will lose his fucking mind if Darling's in danger. Like the instant he sees it, he's got two responses: If they're in an open space, he's gonna Titan out and squish the fucker. If they're in a crowded spot, he's grabbing the nearest weapon/object and he's not gonna come to his senses until his knuckles are bleeding and they ain't got no face lmao.
Tbh he's going to be more hysterical than Darling. Once the enemy's dealt with and not even twitching, he's gonna immediately rush over to them and start crying as he envelops them in a hug. He's apologizing over and over for not getting there sooner, for letting this happen, promising that he won't ever let them out of his sight again, etc.
He snaps out of it a bit when he feels Darling slowly move their arms to hug him back, and when they reach up to kiss his cheek and rest their head on his shoulder he forgets how to breathe for a second. Are they...is he dreaming? He's had dreams like this before. He rescues them and they confess the love they've had for him this whole time, and then they make love over and over, and have so many kids together in a nice house in the countryside away from everyone else.
The fantasy doesn't play out quite like that, but Darling does thank him for saving them and apologizes for not being more careful. He refuses to let them think this was their fault, but what's more pressing to him is the fact that he is now ROCK HARD. He'd quickly take Darling back home and is extra handsy and affectionate the whole way there, and once they're inside he's launching them onto the bed and making at least one other part of his fantasy come true.