Megicula looked around as she was in the 1st layer of the Underworld to collect a few Devils for her experiments.

A voice reverberated. "Megicula, your reign ends now." She turned to see the three low-rank Devils of the 1st layer, both preparing their magic, but it was being combined in two, though she had no idea what their magic was.

"So you want to fight me together, huh?"

"Yeah."

Megicula scoffed. "Seems you have chosen death."

She activated her curse, killing them as she looked up, feeling a summon. But unexpectedly, a beam of light hit her as she felt a strange sensation. Unbeknownst to her, the three Devils had combined their Soul, Mind, and Heart Magic, which would very slowly and subtly, but permanently, change her mind over the years.

Megicula looked as she stopped; one of the Devil's hearts had survived. She cast her curse on the Devil so it didn't regenerate, and then took it for experimentation.

Ten years later

3-year-old Asta looked as he was roaming the jungle. He had left the orphanage after a fistfight with Yuno and Orsi about his magic. As he stood on the ground and jumped, suddenly the ground disappeared from his feet as he started to fall.

"Ehh! Ahhhh!" Asta screamed as he fell. Suddenly, the sky darkened as black clouds swirled around him. He then looked down and was confused, as now the ground beneath him had no green—it was black or bone white, with purple light falling on it. Then, he went splat on the floor. His body broke, and blood leaked; it was a miracle he had not died from the fall.

Asta groaned. "Help, please help," as he lifted his head and heard some footsteps.

"Well, ain't this interesting." Asta looked to see what looked like a weird dress. He looked up, and his eyes widened in horror. In front of him was something inhuman with the figure of a woman with a pale white face, three eyes with red slit pupils, dark patches around her eyes, long pointy ears, and long wavy light-colored hair that seemed to turn into mist. Along with a pair of large curved ram-like horns sprouting from the top of her head and a pair of thin upward-pointing horns sprouting from her forehead. There were also light-colored tentacles, some with dark-colored spots at the tip, covering her entire body, plus a pair of bat-like wings that had multiple large eyes and a long thin tail with a heart-shaped tip.

"W-What are you?"

POV: Megicula

Megicula looked in front of her at what was surely a human child in the Underworld.

The boy looked at her in horror and uttered, "W-What are you?"

She grinned. "Hoo, a human in our realm. How rare. Tell me, boy, how did you enter the Underworld?"

"U-U-Underworld? What?"

"Yes, now tell me, how did you come here?"

"I-I don't know, please help me, it hurts."

"I'll help you after you tell me how you got here."

"I don't know. I just fell through the ground."

"Is that so?"

"Yes."

"Hmm, very well, a bargain is a bargain," as Megicula touched his head. Soon, markings spread all over his body, which started to put itself back together. In a few minutes, Asta was healed.

"Wow, how did..." Asta was cut off as Megicula tapped him, and he fainted.

Megicula looked in curiosity as she looked up to see metallic parts in the sky that she knew were the gate seal of the Underworld.

"I see, it's interesting you managed to cross the gate without any magic. Since I cannot sense any magic in you, or rather, were you able to cross the gate because you had no magic at all? I wonder."

She then quickly used her magic to make sure no other Devil saw or sensed the boy in any way. She took him to her castle in the first layer of hell, as she had made one castle in every layer of Hell using lower-ranking slave Devils made just for her experiments on weak Devils.

Megicula put a curse on him so he would not wake up and would have high-speed regeneration. She looked at him. "Now let's see what makes you so unique." She lifted her hand and cast her magic: "Soul Magic: Scanning." She used her new magic attribute she had gained ten years ago when she ate the heart of a low-ranking Devil to see what it tasted like but found that her magic power had increased. She had gained the Devil's magic, which made her experiments even more informative and entertaining.

After her magic worked, she picked up a blade and dissected him.

A while later

Megicula looked as she finished healing Asta. "It seems by a quirk of fate, you don't have magic, making you special yet not at the same time."

Asta woke up, feeling a jolt of pain. His eyes wandered to see a room of some kind as he tried to move, only to find his body now chained up.

"Well, seems you are awake, boy."

He turned to see the being who healed him. "Who are you and where am I?"

"Seems you are ignorant. I am Megicula, one of the highest-ranking Devils in the Underworld."

"W-What? A Devil, like the one the First Wizard King fought?"

"Quiet, boy," as she glared at him.

Asta gulped. "W-What do you want?"

"Nothing. It's curious. Even after I turned you into a Devil, you have no magic. Why is that?"

"W-What? You did what?"

"Yes, look for yourself."

Asta got up and looked down to see a bucket of blood. He could see his reflection with his face covered in black markings and horns. He looked at his hands, which were pitch black, and his body was different. "W-What did you do? Why?"

"I was curious."

"Undo it NOW."

"Such stupidity. But if you don't like it, you are useless as a Devil anyway." Megicula snapped her fingers.

Asta suddenly felt pain as he writhed on the solid rock bed. A while later, he stopped and looked at his hands to see they were normal. "What do you want?"

"For now, to know about you and why you can cross the gate. I have a theory. It's because you are mana-less, you can cross the gate."

"Can I go now?"

"Only if you form a contract with me."

"What? A contract?"

"Yes. Normally, I would have just possessed you, but that has no merit. So for now, I shall make a unique contract with you. It's easy. You get my power in return for having to follow my commands. Every time I tell you something, it's absolute. You can do as you please the rest of the time, but my absolute command, you have to follow."

Asta nodded.

"Good. Now we shake hands." Megicula extended her hand, and Asta shook it. A rune formed on Megicula's hand and on Asta's neck.

Asta looked at her. "Can I go back now?"

"After this." She pressed her hand on Asta, casting a few of her curses on him. A few minutes later, she let go.

"What was that?"

"Oh, just a few upgrades. Now sleep."

Asta fell asleep as Megicula put him in bed.

Megicula then went to the Sixth layer and found her target, a male Devil. She fought and defeated him, then made the Devil her slave. She took out his heart and soul, killing him. After that, she defeated a Female Devil and cursing her to be her slave as well. She then used her Curse's, which she had modified using the data she gotfrom analyzing the Two Demons in the Spade Kingdom as She turned the female Devil into a Demon with four arms, three eyes, and huge wings. But it was not a giant, justbigger than a normal Devil.

She then forced them to mate, as her curse ensured that the Devil-turned-Demon got pregnant. She cursed her so that the pregnancy was accelerated until the half-Devil, half-Demon hybrid was born. She then used her Curse's to fasten the growth of the child until it was a full-grown adult. She ripped out its heart and soul, killing it, while she freed the two Daemons and turned the Daemons back into Devils, erasing their memories using her curse to rip it away from their minds and souls.

She then went to her castle on the Seventh layer, grabbed her twin sister's heart, and took the three hearts with souls in them. She then cast her Soul Magic on them, purifying both the souls and the hearts.

This was something she learned when experimenting with her new magic. When she had a brilliant idea of reversing a Devil's magical attribute to see if the seal would let them go, she used her Soul magic to purify a Devil's soul. However, she found that the purified Devil also died when its body hit the seal.

Megicula then used her Soul and Curse-Warding Magic on the three purified souls so that they became magicless like Asta.

She then went to the 1st layer and ended the curse she had placed on Asta.