Reincarnation of a Supreme Demon as a Miserable Child

In a distant land, where people are born with various and amazing magical powers, a talented individual emerged. This person became the best magic user and naturally made many enemies. In the future, it was revealed that the best magic user was a demon who had taken on human form to learn from humans. 

"My name is Kazariss, from now on, all of you humans must obey me, or else anyone who opposes me will be punished in the worst possible way," said Kazariss.

 At first, the people of the city mocked Kazariss.

 "Who do you think you are?" someone said, laughing. "Why should I listen to you?" another said, with great pride.

Suddenly, Kazariss killed two people with an otherworldly power. The two were killed with blood on their neck.

The people watched in fear and terror, paralyzed by the sight and unable to move.

Kazariss proclaimed, "From now on, all the people of this land must obey me; you will all be my servants."

Kazariss built a vast empire, and people lived under the shadow of this empire. Anyone who opposed this empire was severely punished. Humans had only two choices: become slaves to the demon or face terrifying punishments. 

"That's interesting, so the demon's name is Kazariss." After saying that, he smiled. 

A young man, with white hair and blue-green eyes, leading a large army, along with other soldiers, rode on horseback towards the castle where Kazariss was. He wore knight's armor, with a red cape fluttering in the wind behind him.

 Kazariss eagerly said, "I haven't had a worthy opponent in a long time; I gladly accept the challenge you have given me!" 

Kazariss and his men engaged in a great battle. The battle was fierce and long, and both armies were nearly equal. 

Kazariss was watching the soldiers from afar when his eyes fell on a knight, the one with white hair. Kazariss excitedly said, "You are

 mine!" and laughed.

 Kazariss dismounted and rushed towards the hero. 

The hero, surprised to see Kazariss, said, "So you are the demon lord, you have beautiful golden eyes." Then he smiled. 

Kazariss replied, "You rebelled against me; don't think flattering me will change my mind." He then smirked. 

The hero's eyes sparkled, and with great greed, he said, "Show me all your power; I am looking for a powerful opponent!" Then he laughed with great excitement.

 The demon and the hero stood facing each other, ready to fight.

Kazariss attacked the hero with magic. The hero deflected the magic with his shield.

 "Interesting, so your shield can nullify magic," Kazariss said with a smile. Kazariss quickly rushed towards the

 hero. To defeat the hero, he had to get past his shield to attack him. 

The hero smirked and said, "If you can, get past my shield!" 

Kazariss struck the hero's shield hard with his sword, shattering it into pieces.

 The hero was surprised and said, "Too bad, that was my best shield." Then his excitement grew, and he chuckled under his breath.

 Kazariss proudly said, "I'll show you the true power of the Demon Lord!" Kazariss gathered a lot of magic in

 his hands to attack the hero. Suddenly, his hands were sealed with binding magic. 

Kazariss, surprised, said, "What?! What kind of magic is this?!" 

The hero smirked and said, "How does it feel to find someone stronger than yourself?" 

Kazariss replied, "You want to kill me, don't you?"

 The hero said, "My name is Lyotan, remember this name well so that you won't forget me even in hell." He said this with terrifying eyes. 

Kazariss angrily said, "I swear that even if I'm killed by you here, I'll come back one day and make you suffer in the worst possible way!" 

Lyotan smiled and said, "I eagerly await that day."

 Kazariss thought, "There's only one way, I have to use reincarnation magic!" 

Lyotan killed Kazariss with his sword. After Kazariss was killed, a bright magical aura emanated from him.

 Lyotan said, "Wow, what a beautiful death, just like those beautiful eyes." Then he smiled.

Kazariss saw a scene of dried, leafless trees. He looked at his hands, which were much smaller. 

Kazariss: "Huh? Where am I?" 

"That kid is still alive!"

 "We need to take him to a doctor!" Kazariss: "Are they referring to me?"

 Suddenly, Kazariss noticed his

 clothes were bloody. 

A woman approached Kazariss and said, "You ungrateful child, how dare you try to kill yourself?!

" She was very angry. Kazariss: "Huh?" A man came towards them and said,

 "How can you treat an injured child like this?! We need to treat his wounds quickly!" 

The woman put her hahind on her hip and angrily said, "You got lucky this time, but when you get home, I'll deal with you." 

Kazariss thought, "This kid has a terrible life, why does he let this woman treat him like this?" 

They took Kazariss to a doctor to treat his wounds. Kazariss sat quietly and calmly on the chair. 

The doctor looked at Kazariss in surprise and said, "It's impossible, with the blow to your head, you shouldn't have survived!"

 Kazariss thought, "Did I reincarnate into the body of a child who tried to kill himself?!" 

Kazariss was a bit shocked but also somewhat pleased. 

Kazariss: "It seems like a miracle, doctor, you can heal me, right?" 

The doctor smiled and said, "Of course, with a special kind of magic, I can heal any wound, no matter how deep."

The woman took Kazariss to her home, which was a bit old and worn out. She treated the child, into whom Kazariss had reincarnated, like a servant and mistreated him. 

The woman said, "Nice try, Karil, but you're really unlucky and pathetic that you couldn't even kill yourself." She said this with a sneer. 

Kazariss thought, "Karil, so that's the name of this child." 

The woman grabbed Karil's wrist and threw him into the basement. 

She sneered and said, "Stay here for a few days, and you'll learn to be obedient." 

She closed the door on Karil while chuckling under her breath.

Kazariss laughed and thought to himself: "Mistreat me all you want; soon I will show you the grim fate that awaits anyone who crosses the Demon Lord!" And then he let out a loud, evil laugh.