The Start
It is theorized a child chooses their parents. Be them great or born to failure, yet she chose the right ones. She picked them because she knew they would do their finest job in having her. That they'd go through hardship together as best as they could. What she didn't expect was another atom to choose them as his parents at the same time. They would be fraternal twins and these two beings were okay with that.
Yet another creature saw power in her atomic making. Satan had been alone for many years. From the beginning of time, all he had was himself and his demons. He got so lonely he created children out of his own soul. Mephisto and Lucifer being the first of many. Even still, he was bored with ruling Gehenna, but he knew he couldn't go to Assiah. He pondered and figured out that if his children utilized human hosts compatible with their matter, thereby he could do the same. Satan only wanted a family. A family that could help each other thrive and become powerful. It was only by accident that he saw into afar, where she was before being born.
Satan saw potential in her. She wasn't human at all nevertheless choosing to be born to human parents. She was different than anyone he'd ever seen before. He saw she would have a taste for fine blood. Further more brutal to those against her but kind and generous to family and friends. She would make a great queen; a great ruler to her people and he wanted to ensure she'd have all the power she needed to achieve that. So he combined some of his DNA into her, making him her father on top of her biological parents.
The pregnancy for the omega, Hizashi Yamada was difficult. Not because it was his first born, no he had an older son, Dabi who was three years old at the time. It was hard because it was his first time birthing twins. Hizashi had awoken in the early morning hours where dusk was approaching. He was restless. Would they be born healthy, would one or both be stillborn, would he have to leave his alpha alone with their children if he died on the table? His scent had gone sour. He couldn't do this, the hospital made him anxious and he didn't want to worry Shouta more that usual. Who, mind you was sleeping right next to him; his body pressed against the omega. Sadly even in the alphas sleep, he could smell his distressed mate. Letting his scent out it calmed Hizashi to a more comfortable level. He'd be fine, when the time comes, both the mates would pull through. He was sure of that.
When the labor did approach, it was only a few days later. The good thing was, was that he was home instead of in his class at UA. Since he lived close to both the hospital and UA, he decided to wait for Shouta after he called him. Once home, Shouta walked them both briskly to the emergency room. The labor was much, much longer than before. Ten hours of pure abdominal pain. it was awful, he's pretty sure he cussed his alpha out too. Which to be frank was rare, he hated cussing especially when Shouta would do it, but that's not the point. Later, when it was finally time to push. He cried tears of joy and happiness. Soon would he be able to see his pups. The first one out was his son. A beautiful and healthy 8 pound boy. Black hair just like his dad with pearly white skin. He was worthy of the name Kaneki. He felt sweet relief for two minutes until he felt the calling of his daughter wanting to come out. She was gorgeous. a head full of black/blonde hair and whopping 7 pounds. They hadn't had a name planned out for her like Kaneki, however they knew the second they saw her that her name would be REDACTED.
Going home, Both the mates were happy. They couldn't wait to show Dabi the twins. Dabi would do a fantastic duty at being a big brother. But Shouta was worried. He knew about Hizashi's family history. And he was waiting for the inevitable to happen. But he couldn't gauge when it would. His omegas history was something you wouldn't expect. As early as humans can remember, there has always been someone of high power. Each one named Demon queen, not because they were of demon lineage, but because they were strong. Only one demon queen could exist at a time. If one died of natural causes, suicide, murder etc., then the next son or daughter would conveniently become pregnant to ensure the title goes on.
Regardless, deciding who would become the next ruler was weird. It would skip one or two generations, allowing the queen time to thrive. Though the deciding factor would never choose the first born child. It was always the middle child and that child had to be born an omega.
Shouta understood it was going to happen to one of his kids since it skipped Hizashi's last generation. And quite frankly, he figured it would be one of the twins. Except he wouldn't possess the ability to figure out which one would be chosen until they were at least 5 years olds. Unfortunately, he was engrossed in what exactly being a demon queen would entail in todays current century. Every queen would become substantially stronger and each one was never the same. If one was human, then the next one would be some type of creature. Always different quirks (powers) and sometimes even quirkless. Moreover, that meant the bullying and/or the segregation could get worse. The alpha had no issues with their kids being any sort of creature. He just didn't want his pups to experience that mistreatment whether it be by friends or strangers. He pushed these concerned under the rug, keeping his mind on the current much happier present time. All he needed to worry about now is changing diapers, feeding his family and ensuring no idiotic wannabe teenagers thought becoming heroes was easy and without consequence. He was happy and that's what mattered the most.