There is some violence in the chapter

"At least Zeref gave us a nice punishment," Sting says, dusting the books in the maths section in the library.

"You call cleaning a library a nice punishment?" Rogue asked his twin brother, pulling out a maths text book and dusting it.

"It better than Acnologia's punishment."

They could still hear the echo of Acnologia's cries for mercy coming from the weapon's roOm. Both brothers shivered at the thought of what Zeref was doing to the oldest Dragon Slayer.

"You're worried about Acnologia but you're not worried about me?" Natsu's voice whines. "Spending three hours as a book makes your bones ache."

Sting smirked as he pulled a gold book with the name E.N.D. on the front out from between two maths text books and smirked at it, opening it up to a random page.

"Hey, don't read me!" Natsu's book yelled. "I'm not an actual book you know!"

"We should write some stuff in here Rogue," Sting laughs, walking over to the dark haired boy. "I remember when Zeref used to write manners into the books."

"Natsu made us rip those pages out too," Rogue says. "Do you think if we give Natsu a new personality Zeref would reward us?"

"Excuse me," a voice says. "Lord Zeref told Mard Geer to make sure Master E.N.D. was fulfilling his punishment like he's supposed to."

Mard Geer, one of Zeref's oldest demons, appeared from the shadows. He walked to Sting and took the Book of E.N.D. out of his hands and put it back into the bookshelf.

"Mard Geer, why didn't you put me into the children's section?" Natsu whined.

"Mard Geer was told to put you in the maths section by Lord Zeref," Mard Geer says, turning away and disappearing into the shadows. Sting and Rogue stared after him.

"Can we turn him into a book and write in it to make him stop talking in third person?" Sting asked.

"No," a new voice says. "Natsu was the one who wrote that when he was newly revived as a joke."

Sting and Rogue turned to see Zeref standing behind them, holding Natsu's book to his chest. Natsu was whining something to him but he ignored him.

"Zeref, it's been three hours now!" Sting whined, pointing the feather duster at the Black Wizard.

"Yeah, it's been three hours now!" Natsu's book whined. "Can you please put me back to normal!"

"Sting and Rogue, your punishment was to clean the library until it is spotless regardless how many hours it takes," Zeref says to the twin Dragon Slayers. And to Natsu's book, "and Natsu, since you won't stop whining you are to become Sayla's and Kyôka's slave for another three hours."

"Oh come on!" Natsu whined. "Kyôka would practise her Curse on me and Sayla would use her Curse to make me do what Kyôka wants me to do!"

"Another three hours would be added for that," Zeref smirked. "Sayla! Kyôka!"

Out of the shadows two female demons appeared. One of the demons had green hair and looked like a bird. She was wearing a dark cloth on her upper body that partially covers her chest and wraps around her back and detached sleeves with three bulb-like adornments, a dark thong and studded belt around her waist, as well as detached dark pants that begin mid-thigh and end where her aviary feet begin.

The other's most noticeable feature being the two large gold-looking horns protruding from the sides of her head and pointing upwards. Upon her head is a white band which separates her hair, framing her bangs from her hair below the band. Worn upon her forehead is a small circular symbol with a small dot on the inside and surrounded by several dots around the top. Tied around her neck is a small white-colored strap. Meanwhile, Seilah's attire consists of a very revealing beige-colored leopard-printed kimono, bearing the decorative marks on her shoulders. The kimono is wrapped around her torso with a thick, decorative yellow ribbon that ties behind her back, and her outfit is complemented by thigh-high socks that reveal her heels and toes.

"You can have fun with Natsu for six hours," Zeref tells them, handing the book to Kyôka. The book turned back into Natsu and he instantly found himself in both female demon's embrace.

"Thank you Lord Zeref," Kyôka says, grinning.

"Lady Kyôka can have the first three hours and I'll have the last three hours with him," Sayla says, blushing slightly at the thought what she and Kyôka would be doing to their master with their creater's permission.

The older demons dragged the younger demon away, who was whining the entire way.

"I'm never going to be the same again," Natsu sighs as he collapses beside Acnologia, hickeys and scratches lining his body.

"Yeah," Acnologia agreed, wrapped in an endless amount of bandages so that he looked like a mummy. "Remind me to never disobey Zeref again. If I seem like I'm going to, hit me."

"As long as you remind me to never get on Zeref-Nii's nerves again," Natsu sighed. "I'm so bored. Want to destroy a Kingdom with me?"

"Sure, why not," Acnologia mumbled.

The demon/Dragon Slayer and the other Dragon Slayer left the throne room, Zeref watching them from his throne. Invel stood to one side and August stood on his other side.

"Are you sure it was a good idea to let them go destroy a Kingdom your highness?" Invel asked.

"I've learnt to never stop them from destroying a Kingdom," Zeref sighed, rubbing his temples. "When their set on destroying a Kingdom, they will destroy a Kingdom. Anyway, what's the news you've got for me?"

"Fairy Tail are forming an alliance with the kingdoms Blue Pegasus, Celestial and Lamina Scale your highness," Invel says.

"Hmm." Zeref gets an idea. "Invel, go tell Natsu and Acnologia to destroy the Celestial Kingdom, and tell them to kill King Jude and Queen Layla too."

"Prince Natsu! Acnologia! The highness wants you to destroy the Celestial Kingdom!" Invel yelled at the top of his lungs.

"We were planning on destroying that one!" Natsu yelled back.

"That kingdoms been in my To Destroy List for months!" Acnologia put in. Acnologia and Natsu jumped out of the window, Acnologia turning into his dragon form and Natsu into his Etherious form before disappearing from sight.

"Use a door!" Invel yelled.

Zeref sighed and shook his head. "Even though they're both over four hundred years old they still act like children."

"Acknowledger, why ... are we on ... a train?" Natsu asked as he hung out the window, his face green with motion sickness.

"Because ..." Acnologia muttered from beside him, also hanging out the window and his face green with motion sickness too. "I want to ... take the ... Kingdom by ... surprise. And my name urk ... is Acnologia."

Even though Natsu was a demon and Acnologia could destroy a Kingdom if he wanted to they were still Dragon Slayers. And Dragon Slayers plus transportation equals dreaded motion sickness.

"Then why ... can't I go ... into my ... Etherious form?" Natsu muttered. It seemed that the motion sickness didn't bother Natsu in his Etherious form. Than again motion sickness didn't bother Acnologia in his dragon form but he couldn't exactly just turn into a dragon on the train. He'll have to brave the motion sickness.

"Because if ... someone comes ... urk ... in here ... you don't want them to ... freak out at the sight of your ... ugly demon form ..."

"It's called an ... Etherious form ... and it's not ... ugly."

After that they stopped talking as the train headed for the Celestial Kingdom.

While some kingdoms, like Fairy Tail and Alveraz, hold wizards with different types of magic there were kingdoms out there that only had wizards that could use one type of magic. The Celestial Kingdom was one of those kingdoms.

The Celestial Kingdom was a Kingdom for Celestial Wizards which was located in the heart of Fiore. Unlike most kingdoms it didn't have small guilds but towns where the inhabitants got work and money from running restaurants and all that other stuff with the help of their Celestial Spirits. In the heart of the Kingdom was the palace, where the King and Queen, Jude and Layla, lived with their daughter Lucy. The Royal family of Celestial were the only ones who had contracts with the Zodiac Spirits.

"Woohoo!" Acnologia and Natsu declared as they ran off the train after what felt like an eternity of dreaded motion sickness. If people saw how they were acting they would not have believed they were the Demon Prince and the Dragon of Apocalypse and would have laughed in your face.

"Where should we start first?" Acnologia asked, cracking his knuckles and aching to destroy something.

"You take the sky Acknowledger -"

"IT'S ACNOLOGIA!"

" - and I'll take the ground."

Acnologia shifted into his dragon form and flew into the sky, disappearing behind the clouds. Natsu shifted into his Etherious form and ran into the town, sending black-blue flames as he ran. Fire engulfed the street, the scent of fire and burning flesh filling the air and the sound of a demonic laugh echoing through the street. The Celestial Wizards ran around screaming for help, begging the Celestial Spirit King (who's their god) to save them. Natsu snatched a random human off the street and flew him to the top of a building and sunk his demon-sharp teeth into his jugular vein, blood running down his chin as the man slumped forward, dead.

"What is going on here?!" King Jude boomed, trudging over to the window. His eyes widen when he saw his Kingdom ablaze. He looked towards the sky when he heard a frightening roar and saw the black dragon with blue markings flying around, sending attack after attack towards the towns underneath.

"Jude," Queen Layla says, looking over at her husband with a knowing look. Jude nodded to her as he left, going to protect his Kingdom. Queen Layla pulled out a silver key from her cleavage and held it up, the key glowing with magic as she summond a spirit. "Open, Gate of the Protector: Alistor!"

A man wearing glasses and way too long hair to be a man appears, holding a book. He looked up in confusion and, realising that he had been summoned, put the book away and stood to attention.

"Alistor, I want you to do everything in your power to protect my daughter," she ordered. Alistor nodded and disappeared. Layla sighed and summoned another spirit, a messenger to go to Fairy Tail to ask for help before going to join her husband in battle.

"All these people taste disgusting!" Natsu whined as he wiped a smear of blood off his chin, trudging through the streets of Celestial. "There has to be someone who tastes nice around here!"

"You're asking me if there's someone nice around here?" Acnologia's voice booms from the sky which was lightening up with something that was not fireworks. "I'm not a fucking cannibal like you, you little brat!"

"I AM NOT A CANNIBAL!" Natsu roared to the flashing sky. "I AM NOT HUMAN! IT DOESN'T COUNT!"

"Yeah, yeah." Acnologia rockets towards the ground and lands in front of Natsu, creating a crater under his dragon feet and causing some buildings to collapse and some dead bodies to fly around as if they were rag dolls. "Why don't you try one of the Royal family members? Their rumoured to have pure celestial magic running through their veins. One of them should taste delicious to you."

"Perhaps you're right," Natsu agrees, taping a claw to his chin and accidently drawing some blood. "Thank's Acknowledger."

"Acnologia! My name is Acnologia you shitty little brat!"

"Yeah, yeah." Natsu rolls his eyes as he took off towards the castle, sending torrents of demon flames towards the city from his wings on the way. Natsu sniffed the air, smelling some young blood coming from one of the windows. Natsu smiled manically and flew through the window, landing on the ground in a crouch, his talons digging holes into the pink carpet.

A feminine shriek caught his attention to the corner of the room where a teenaged girl was cowering by the wall, arms over her head. From what Natsu could see she had blonde hair tide with a pink ribbon to the side and was wearing a royal blue dress with ribbons crossing her chest. A little creature that looked like a snowman was clutched in her arms too. Natsu knew instantly that it was one of her Celestial Spirits due to the scent coming from it.

"You're not like her," Natsu sighed, scarlet hair drifting in the corner of his mind as he walked towards the girl.

"H-her?" the girl questioned, looking up at him with teary brown eyes. Her eyes were brown like Erza's but they weren't the same.

Natsu grabbed her neck in a death hold, causing her to choke as he got closer to her face, flashing his demonic fangs at her. The girl was a trembling mess now, trembling so hard that Natsu thought that she might break in half. She wasn't Erza but she would have to do.

Princess Lucy of Celestial felt the pressure of the Demon Prince's fangs on her neck where it met her shoulder which was exposed due to her dress being an off the shoulder dress. The Demon Prince's fangs pierced her skin, causing her to scream out in pain as a searing pain shot through her body. It felt like the fire demon was spreading fire into her veins, spreading it, devouring her blood as he spread that fire. Lucy could feel her life being drained away, could feel her blood being drained. Was the Demon Prince really a demon? She never knew demons drunk blood like a vampire.

As Natsu drunk more and more of the princess' blood her body went limp in his arms until he had had enough. He dropped her body and stood up, wiping her blood off his chin as he made his way towards the window. However he stopped dead in his tracks when he heard a groan come from behind him. Turning Natsu saw the princess struggling to get up, blood running down her neck from Natsu's bite mark, staining her golden hair and dress.

So she had survived his bite? It seemed a new demon was now roaming the land. Natsu wondered how many lives the Celestial Princess would take. He actually had the urge to take her with him, to make her his Demon Princess.

No, Erza would become my Demon Princess, Natsu thought, surprising himself.

Not wanting to see the newly turned demon Natsu jumped out of the window, disappearing into the sky.

Meanwhile Princess Erza arrived in Celestial on the back of her legion, dressed in her captain uniform. She watched the blue-black flames, instantly knowing what was going on.

Natsu was here.

And she wanted to see him despite the fact he was destroying the Kingdom.