Sharing the thoughts of the person who wrote this post here (please go read what they write), I also agree that Batman/Bruce needs a good motivation to become obsessed with someone, and I'm here to present my idea of a Darling for Batman (this is heavily related to a fic I'm writing that's clearly based on an OC that's still under construction, but I'm still writing the story x reader, although of course there will be some physical descriptions that can't be changed); where it would be a Batmom Reader (with a possible spin-off, the Batsib Reader)
And although I know the "neglected reader" (for platonic yandere but also can go to neglected Batmom) trope is very fashionable (not gonna lie, y love it too), I honestly prefer to write the "former villain reader forced to redeem herself" or "villain who tries to reform herself but does it in such a poor way that no one would believe she's genuinely trying" trope.
So I'm presenting this concept, and I've already written some of my lore about aliens who are basically my version of vampires (you can read it here, here, and here; however, there may be changes in the future, mostly in their alien form). Also, even though I'll be writing the story in a fanfiction style, I'll be heavily based on my OCs, so it will be, first of all, a fempov story.
Second, there will be a lot of lore and worldbuilding involved, so the amount of information I give out might be overwhelming at times. Third, there will be changes to the canon (well, something obvious that usually happens when you write fanfiction, but it never hurts to warn you).
So this is the general idea, or at least part of it. You know I'm not good at making short posts, and even for a small concept I take quite a few paragraphs.
We're talking about a creature made of darkness and magic, an Umbratra, whose life after the destruction of its planet was simply to adapt to the dominant civilization (which I'll talk about later since it's a species I created not only for another fandom, but for a story with original characters) that captured them and that formerly saw them as nothing more than music boxes and breeding stock (yes, Umbratras were used as breeding stock as soon as they reached maturity), until one of the high command saw the talent you possess to imitate any society you enter and adapt in a way that almost makes you seem like a native inhabitant of the species.
Alongside the fact that you are a being who possesses high-level magic, that you are basically one with magic, so you don't even need to cast spells and can use said magic to change your appearance and perfectly imitate (clearly not on the first try since you're a kid for now, but after much observation, research, analysis, trial and error) the appearance of the chosen species to integrate into, which they decide will be the empire's spy force, in charge of infiltrating and investigating planets and other species that can serve the dominant species for reproduction since they are having fertility problems among themselves (a story for another post) and the Umbrata they are using are not enough to increase their numbers, not only that, but you must also find things to entertain them since that superior species, which we can treat as cosmic regulators in the great universal ecosystem, gets bored easily and bored = hungry, not a good thing.
As for you, fortunately your superiors don't wait for you to reach maturity; even as a child (500 years in human time is still classified as childhood) they send you on infiltration missions where you diligently carry out your mission to prove your worth to your superiors, especially to gain the favor of the empress and thus be accepted as one of her own (basically, you try to earn your citizenship); you have already been to several planets, such as Tamaran, Krypton, among many others, but your last mission to be accepted into the society of what -for now we will call devourers-, sends you to a very distant planet where there is reportedly ice (a delicacy for your superiors); at this point you're 1000 years old and only reaching your early teens.
In addition, the Devourers' oracle (let's call her their religious leader) mentions that the species on that planet is highly compatible with many alien species, including, clearly, the Devourers, but that they are still too underdeveloped to be of use to the empire. Therefore, it will be your job to help humanity progress to an optimal point where the Devourers see the abduction of humans to take them to the breeding farms as viable. In case of failure, the Devourers will consume the planet and everything on it (as they did with your home planet, Tenebrae Prime), and you too will end up in the stomach of one of them after being used a few times in the breeding farm (so, you know, no pressure).
You arrive during the Crusades and experience various historical events, sometimes participating in them or triggering them, all in service of the mission. However, the mission is not easy, since despite having imitated several species and learned their behaviors, you have never learned to have your own emotions. After all, you have never stayed long enough on a planet other than Baratros (the home planet of your devouring masters) to become so deeply familiar with other species. But in this case, your stay on Earth will last 1500 years (which will mean you live your adolescence and young adulthood among humans).
You will dedicate yourself to the field of medicine since your main mission is to ensure that humanity adapts and evolves to be as receptive and compatible as possible so that the Devourers can reproduce with them; of course, behind the scenes you will also be looking to see if your own species is compatible with humans, after all, you are few and those who have reproduced with the Devourers, over the years lose their Umbratra genes (because Devourer genes overwrite any DNA weaker than their own, which is technically all other existing DNA) which puts your own species in danger of extinction as well.
Anyway, I can't say more because it would be a spoiler for the story, details that will be revealed in flashbacks or with other characters (for example, you know Vandal Savage and Ra's al Ghul more closely than other characters since you've interacted with them in past centuries), but I want to make it clear that you're not good, nor bad, but there will be times when the bad things you do over time will be despicable, when you learn to have emotions and feel like a human being, something that won't always be entirely good, but you will learn to regret your actions and try to do better.
Even so, making it clear that you are someone who for a long time will operate under the philosophy of "the end justifies the means" and thanks to that you do very bad things, as well as very good things, in a way that you cannot be classified as a good or bad person, you are a gray area difficult to classify even for someone like Batman (which will make him obsessed with you and not let you go; after all, he will feel that even though you are no longer that horrible being you were in the past, you are still too dangerous to leave without his exclusive watch on you).
And no, you don't want to know what you were doing between 1939 and 1945. That's something only you, Alfred, Wonder Woman, and other characters who lived through that time know, and it's not something you want people to find out because it's the lowest point of your existence, when you learned the emotional meaning of hate.
