Blood is Thicker than Water

When Ryou headed back to the study, he dropped everything he brought and fell to his knees, almost throwing up.
“What...is this feeling...? It’s like...” Ryou searched through his memories and gasped. “...like Kurokage’s bloodlust, but million...no, billion times stronger!!” Then Ryou paled as he remembered something. “Kirihime!!!”
Ryou forced himself to stand and run toward the study. His body felt as heavy as a stone and every muscle in his body shouted at him to stop and give up.
“I can’t give up...!! Kirihime needs me! I can’t...I don’t want to disappoint her anymore!!” With extra effort, Ryou reached the door and barged in.
If the air outside was already heavy, the air inside the study felt suffocating, as if Ryou was in the bottom of the ocean and he couldn’t breathe. Then Ryou’s gaze fell to a man with his back at him.
He was tall for someone who looked like a middle-aged man, with muscular build and an alarmingly familiar silver hair. But Ryou’s attention was immediately fixated on a small body on that man’s shoulder.
Kirihime, who was unconscious and injured, being carried by that suspicious man, was enough to snap Ryou into action.
“Hey!! Who are you?! Stop!!” Ryou lunged at him.
That man turned around and all of the sudden, Ryou fell to his knees.
“What...? My body...won’t move at all...what is happening here?” Ryou thought in confusion.
“How rude. That’s my line, boy. Who are you?” The man replied with heavy, powerful voice that reminded Ryou of an absolute king.
“Sa-Satomi Ryou. Artificial Mazoku.” Ryou was surprised when he gave the answer out of fear.
“Hmm...so you’re her toy.” The man smirked. “She had some real talent with this, I had to admit.”
“W-Who are you?” Ryou fought his fear and asked a question.
“Me?” The man widened his eyes in surprise. “So you haven’t heard from her at all? Very well. My name is Kojou Maou.” He smirked. “The demon king.”
Ryou went more and more pale as he listened to Maou’s words. “Kojou Maou? The demon king? Kojou...so...he’s...”
“Yes, I am her father.” Maou looked so pleased with Ryou’s reaction. “But I’ve had wasted enough time here. Say your goodbye, boy, for you’ll never see her again.”
Those words sparked Ryou’s spirit again. “W-What do you mean?! You’ll take her away?! What did Kirihime say about this?!” Ryou demanded.
Maou narrowed his eyes and Ryou felt his body getting even more pressure from his stare. “I don’t care what that child say. I’m her father and I have every right to do what I want to do. Demons are different from humans, boy. For demon, blood means everything. They who created blood can control that blood. My blood runs in her veins, thus she will follow everything I say.”
Maou turned around and, with one snap of a finger, opened a portal. He walked inside without sparing Ryou another glance.
“Wait!!! I’m her knight!! I’ll protect her—!!” Ryou leapt to his feet, all of the pressure gone when he thought that he would lose her.
Ryou shifted his hands into Aether swords and swung it to Maou. But right before it hit him, someone grabbed Ryou’s arm and pulled him away. Maou chuckled and disappeared, along with Kirihime.