Nothing is like it seems.

To be as brief as possible.
Soon enough, Sid indeed came up with a way to satisfy his needs and instincts without dragging his father's and uncle's rage against himself.
Similarly to Dexter, he decided to target criminals that deserve the horrible treatment he wants to reserve them and to be killed, just, unlike him, to make it even easier for himself and avoid any possible problem, he chose as target, the Aurin of the Wild kind. Why? They are not in the civil registry as they sure don't follow any rule; they live in the wild areas which are not controlled by Elite Guards and Royal Guards; no one among them reports missing people, murderings or any crime to anyone, living truly as wild animals, respecting only the law of the strongest.
But Sid is not really all about killing, mostly as he started to grow up and to feel some specific "need". He is clearly not the type to find a girlfriend, let alone to respect any formality. So, as he started to hunt, between a murdering and another, he started to select a few female Aurin, in the end 3, to actually keep for himself, as his "breathing toys". All of the three are black cats, all of them criminals. Malyka, 29 years old, used to seduce male Aurin to then kill them to rob them. Carlie, 26 years old, "professional" thief who also never hesitated to kill problematic victims. Syha, 21, the "cleanest" of the three who killed only 1 person and robbed a few.
He found them, tortured them badly and then raped them, that way literally "enslaving" them. In order to avoid more tortures and to be killed, they turned super submitted to him, obedient and almost looking as if they were "obsessed" with him. And he likes this. He always fancied to enslave and this "lion pack"-like where he is the "lion" and the women his own "lionesses". It suits him, being a big feline, even though he is no lion.

Sao and Edward know about this, but they won't interfere, because this keeps him from hurting innocent people and is making him more obedient and controlled. But not really less dangerous, mostly if anyone threatens to take them away from him and surely not because he loves them in any way.

One thing Sid doesn't know though, is that Malyka, unlike one would think, is not as alone as the other Aurin. About an year before, she found a little abandoned baby near the corpse of the mother, who died giving birth. She took the baby and raised her as she could, pretending to be her big sister, surely not having a motherly instinct.
After Malyka was taken by Sid, the 1 year old remained alone in the forest, just given some superficial care by other Aurin of the community, but none of them really paid any true attention to the little girl. And the little one is very tied to her "sister" and even though so small, she decides to go look for her, easily sneaking away from the distracted Aurin.
She too is a little kitty and mainly thanks to her sharp sense of smell and the fact that Sid's cave is not far from where she was, she manages to track her sister and reach the cave.
Needless to say the shock and terror of the 3 Aurin when the girl appears there, mainly Malyka's, as she is immediately concerned that their master will kill the little one. And of course, before she could even do anything, Sid arrives there as well, immediately noticing the girl. Oh if he could he would do such terrible things to her, her very presence there angers him, but he knows his uncle and father would gut him for good if he harmed someone so innocent and defenceless.
Malyka tries some desperate actions to let the girl escape but it's pointless, Sid hurts her and pushes her away, grabbing the little one by shirt and lifting her; he then gives Malyka a glare that promises a very harsh time for her when he returns and runs away with the child.
As he has no idea at all what to do with her, he brings her home, handing her straight to Sao, the only person at home at that time.
Of course in a first moment Sao thinks the child is Sid's, but he denies it saying "it calls one of mine, "sister".", then he simply drops her on the ground and returns to the cave, to torture Malyka a bit. Very unfortunately for her, she is his "favorite", which of course means more "attentions" from him.

Anyhow. Sao is even more clueless than Sid of what to do with the child. He has no intention to take her himself as he doesn't want any sort of "replacing what he lost", so, logically, he goes to take her to Edward, trusting he will know much better what to do with this.
He goes with the child to the EG headquarter, finding Edward in his office. He has some words with him telling him what Sid did and said about the girl then eventually shows the child to him. Edward's answer to it is sort of unthinkable. As a matter of fact, after doing his usual thing looking in the girl's eyes, he says. "Take her to Christoph. (Yes, that Christoph), she belongs to him.".
Sao of course obeys, takes the girl and goes to wait for Christoph in front of his mansion in Thylum. When the Anatomist returns from work, he finds the two there and is absolutely annoyed, even though he has not even idea what's the matter. "Take her to a real doctor, if I wanted to be one I'd become one for Gods' sake. -.- "

"If she needs a doctor you will have to find out yourself, I fear. Let us in and make sure we speak privately, you don't want anyone to hear and I won't let innocent ears listen to what will be said."
It leaves Christoph even more confused but eventually lets them in; Sao leaves the child in a separate room while he and Christoph head to his lab to speak privately indeed. There, Sao tells him what Edward said, and of course, it shocks Christoph, who believes it's some idiotic joke probably from his nephews.
Sao on the other hand, is far from a joking type and is rather short in patience. He has no intention to be there to convince him of something he doesn't want to believe, as it'd truly mess up with him badly if it was true, so he simply tells him "Lord Edward said it's yours and you must keep her. Bring your complaints to him and be thankful I and him are the only one to know of this."
Point is, Christoph simply can NOT believe it for one specific reason: he has not done it with ANYONE after his wife's death, let alone with some wild Aurin. How in the hell could he put one pregnant?

After Sao leaves, leaving the girl to him of course, Christoph heads to speak to Edward about the matter, not hoping to have many answers or understanding, but in truth, he is almost scared. If that girl is his, everyone will think he did something with some Aurin prostitute, probably even paying her for it. And that's pretty much illegal, not to mention how it would kill his reputation for good, as he is a high noble and certain behaviours are pretty much ill-seen, something for "lessers".
As expected, all Edward does is to confirm the child is Christoph's and simply suggests him to think very carefully how it could have happened, because the girl exists, like it or not.

In order to find a desperate proof that she is not his, Christoph makes a DNA test. Result? There is a total 100% scientific proof the girl is HIS. He literally panics, starting to think very hard how it is possible. Could he have forgotten? Impossible...
The only dealing he had with an unknown Aurin was...wait, about 1 year ago...but he didn't touch her, the w*ore just robbed him and made a whole mess in his..lab................................

About the mother of the little girl.
She too was a cat Aurin, of the Wild kind and of the worst type. As most wild Aurin, she never wanted to accept any sort of rule, let alone to have a dignified job.
After years of attempting to become rich through thieveries and prostitution, she came up with a plan to make her life rich and perfect: find some rich widowed man and trick him into marry her, so that she could spend the rest of her life like a spoiled and rich lady.
With that in mind, she headed to Thylum, investigating about someone that could be fitting for this. And she soon heard of Christoph. Wife dead since over 20 years, living alone, a Prince, a successful researcher and at the time, a very rich man.
It was late Autumn II and it rained like crazy; she chose a night with the worst storm possible and knocked on his door, looking all poor and wet. She had no idea who she was in front of. (XD) She had to beg a looot to convince him to let her in and not just shut the door on her face, but eventually he granted her to sleep in his basement for the night, promising he would kick her out tomorrow. No, he didn't want an Aurin servant, nor any servant at all.
Disappointed, the womam went to the basement where she tried to come up with some ideas.
Now, that night, Christoph was called with urgence by Doctor Robstein, in need of a very experienced assistant for a very delicate surgery. He was forced to leave the Aurin alone into his house as he didn't have the time to waste to kick her out.
She, of course, took immediately profit of the situation and started to search the whole house to find something to use to seduce him. Bitterly, she had to realize he is still literally obsessed with his dead wife and he clearly will never show any appreciation towards her. So, she decided to rob him, taking the few amount of money he had at home, as the most of it he kept in bank, and everything that could have a value, until she reached his home lab.
The room was filled of vials, samples of every kind- She started to check them to see if there was something valuable, thinking he was an Alchemist or Potionist. But instead, all she could find were rather creepy samples, even some organs in jars. But one thing totally changed her plans and the course of the night.
Now, as a researcher Biologist and Anatomist, Christoph gathered body liquid samples of all sorts, most of which from his victims, but some from himself too. All to be used in experiments and researches, and that included a sample of his own...yes, that.
When she saw it, the idea came very fast. Steal it, put herself pregnant through it, give birth, blackmail the Lord, forcing him to marry her to protect his reputation. The plan seemed flawless and would possibly even work. She was cunning enough to make a whole mess, causing all the vials in the lab to break on the floor, so that he would not even be able to notice he was missing that specific vial.
After destroying everything, she left and disappeared. It was surely out of her plan to die giving birth.

But the fact stays, Christoph has a daughter and now he is literally panicked, not knowing what and how to do with her. He can not give her away, as he fears Edward's reaction, but for now, he is trying to keep the thing as secret as possible, not knowing what to invent. Also, after spending all of his money to give Bart a ship, he can't really afford to raise a child, but he will never say anything about it of course.
And that's also the reason why he called Richard so suddenly and mysteriously. Looking for some serious help as to how avoid to be shamed or dishonored.