It's Not A Mistake

Kushu frantically trying to reach Ryou, who was buried under so many zombies. But he had thought that Ryou was dead—or even worse, turned into a zombie.
BLAM!!!
Kushu widened his eyes in disbelief. Even Hanzoku and Maou who were engaged in intense fight took a glance.
“It hurts, dang it!!!” Ryou rose to his feet, his hands had shifted into a pair of giant hammer. “I won’t forgive you for that!” He kept sending zombies flying to the shrine’s wall with his hammers.
“R-Ryou...?! But...how?!” Kushu stammered.
“I’ve found someone I wanted to protect, that’s all.” Ryou said calmly.
Bruk!!
Both Ryou and Kushu turned around, just to see Hanzoku hit the floor painfully.
“Hanzoku!!” “Old man!!”
The two of them ran to Hanzoku, who breathed heavily.
“As I thought...I’m no match...for Maou...” Hanzoku forced a bitter smile.
“You’ve been weakened so much, Hanzoku.” Maou said haughtily. “The old you would’ve put up much fight than this.”
Maou turned around and snapped his finger. Ryou and Kushu quickly looked around in alert, waiting for another bad surprise. But the only thing that happened was a zombie, who crawled outside the crack and plodded towards the barrier, right into Kirihime’s field of vision.
“That zombie...a woman...?” Kushu muttered.
Ryou focused his attention to that zombie. Though her clothes was tattered and her body had rot, she still retained some kind of dignified air around her. She had long, dark-brown hair that swayed with every step she took. Seeing her made Ryou felt nostalgic, as if he had seen her somewhere.
Then Ryou caught a glimpse of her eyes and he hurriedly dashed at her.
Unfortunately, Kirihime also saw the zombie’s eyes and paled.
“Mo...ther...?” She let out a choked voice.
The zombie stopped before the barrier, but she did nothing to break it. She just put a hand on the barrier, her beautiful deep-purple eyes that were extremely similar to Kirihime glinted as if she had recognized Kirihime.
“Mother...is it...really...you?” Kirihime forced herself to sit up.
She was so focused to the zombie who used to be Emilia that she failed to notice Maou’s movement.
“Kirihime!! Watch—!” Ryou shouted, but it was too late.
Maou flew toward Emilia from behind her and shot a gigantic fireball at her. The fire consumed her rotten body and destroyed Kirihime’s barrier easily. The sound of barrier shattering overlapped with Kirihime’s scream of despair.
“Stupid child.” Maou flew toward Kirihime, who stared blankly at the remains of her mother. “You couldn’t possibly maintain the barrier if your mind was disrupted.” He grabbed Kirihime’s neck and started choking her, who no longer had the will to fight back. “I don’t need you or your mother anymore. I just have to do over and made another child to do my biddings.”
Then Kirihime saw Ryou, who desperately shouting at Maou to stop. She smiled bitterly and mouthed, “I’m...sorry...”
BRAK!!!
“Who the heck asked you to apologize, stupid princess??!!”
Kirihime was stunned when Maou suddenly disappeared and Ryou caught her instead.
“You...how dare you throw my zombie at me?!” Maou spat at Ryou while getting rid of the zombie that Ryou flung at him to stop him. He tried to get up, but the wall he just hit crumbled and halted him.
“Kirihime, I admit that you’re a genius, but even a genius like you could make mistake.” Ryou spoke as he carried Kirihime in his arms.
“Eh...?” Kirihime looked at him in surprise.
“Mazoku is not a mistake.” Ryou said firmly.
Kirihime widened her eyes. “But...you said...you don’t want to be...”
“Yes, I know. But now that I think about it, I was mistaken as well. I liked being Mazoku. After all, the sole reason why I could meet you is because I’m a Mazoku. If I kept being a human, I could never meet the girl I loved.” Ryou smiled tenderly.
Kirihime’s face immediately blushed. “B-B-But...t-that’s...” She stuttered.
“I’m sure it’s not just me. There must be other Mazoku who were grateful because they were born as Mazoku. That’s why...please don’t erase us. Because we’re not a mistake. Okay?” Ryou looked at her.
Kirihime averted her eyes, too embarassed to look at him. “...I understand. Ryou...will you still be my knight? Even when we no longer have any ties...?”
“Then, let’s renew it.” Ryou cracked a smile.
“But...I have nothing I can offer to you...”
“Your life.”
“Eh?!” Kirihime looked up in surprise. “Are you actually a demon?!”
“Not that!” Ryou shook his head. “Give me half of your life and I will give you half of my life. It’s simple, right?”
Kirihime fell silent for a moment, then she smiled and hugged Ryou, hiding her face on his shoulder. “Idiot. If it’s you, then I don’t mind if you take my whole life. Because...I...”
“I’VE HAD ENOUGH!!!!” Maou roared.
The next second, the whole shrine was covered in intense darkness, just like Kurokage’s [Shadow Realm], but few times stronger. When the darkness subsided, a different creature stood where Maou was supposed to be.
“T-That’s...” Kushu, who stayed by Hanzoku’s side, paled.
“I-Impossible...for Maou to use his trump card...” Hanzoku, too, paled.
“Kirihime...is that...?” Ryou asked in low voice as he couldn’t stop shivering from looking at that creature.
“...yes. It seems my father wanted to completely destroy all of us. That...is his true form...capable of destroying a third of this world if he go all-out.” Kirihime nodded gravely.
A gigantic humanoid creature, with pitch-black skin and a pair of demon horn on his head, towered over them. Even all the zombies got goosebumps and went back into the chasm. Maou in his true form as demon king had grown claws and fangs, completed with legs of a goat and giant wings on his back.
“I’ll annihilate all of you...” He growled.