AN: Thanks Goku275, MDM11, and DracoKing30.
Goku275, Zeref learned from Ajeel back in Chapter 78. I even had a brief scene where a single fly died after touching Zeref, indicating that learning the now-dead August was his son had affected the Black Mage more than anyone realized, himself included.
MDM11, I would assume that Shô and Wally are just out living their lives. They are probably staying in contact with Millianna and Erza through letters (maybe not Erza, given how people react to her letters). As for the S-Class part, yeah, I could imagine any of them winning the exam. Especially if they became as strong as they were by the end of the Alvarez Arc or 100 Year Quest.
"Hey, everyone!" shouted Jenny, who was presently steering Christina, through the airship's intercom. "Brace yourselves for a bit of turbulence!"
With those words, she spun the wheel and made the airship perform a sharp turn. Acnologia followed after them, moving away from Magnolia Town.
"And to keep his eyes on us…" said Jenny to herself. Then, to those aboard Christina. "Magical Convergent Cannon: Jupiter, Charged! Emergency hard starboard!"
The airship spun around until it faced the Black Dragon. As it did so, a hatch on the front opened up, exposing a fully charged Jupiter.
"Fire!"
A beam shot from the cannon, striking Acnologia's left wing.
"All right! Bullseye!" cheered Jenny.
Unfortunately for the Pegasus, her celebration was premature. The Black Dragon grabbed onto the beam with his one arm and began devouring it. After finishing the beam, Acnologia then burped, his wing undamaged and his belly so full that it was bloated.
Jenny and the Trimens (they were also in the cockpit — Hibiki for navigation and Ren and Eve on standby) looked at the Black Dragon in horror, only snapping out of it when Acnologia started flying toward them again. Jenny resumed steering the airship, while Ren and Eve began operating Christina's physical weapons.
"I doubt it'll do much, but… Eat 120mm of hot lead!" shouted Ren, manning the controls for the artillery on the airship's right side.
"Assault Pegasus!" cried Eve, operating the left side artillery as Christina's physical cannons activated.
The new assault didn't fare much better than Jupiter did, though. Acnologia easily maneuvered through the storm of ammunition, not slowing down as he avoided every single shot. In fact, the Black Dragon actually sped up, burning the Magic Power that he had just consumed to do so.
"Do you really think you can outrun me?" bellowed Acnologia, the gap between him and the airship steadily closing.
"Fire up the Magic Booster!" shouted Hibiki.
Redirecting their Magic Power from the artillery, Eve and Ren activated the Magic Boosters, and the distance between them and Acnologia started to grow once more. The Black Dragon continued to chase after them in spite of this, just as Blue Pegasus had hoped.
Meanwhile, in a different part of the airship, Erza, Wendy, Jellal, Ichiya, and the mystery woman got up after being knocked down by the Magic Booster's activation. Wendy, her motion sickness fading because of the ship's dragon slayer accommodations, was finally able to get a good look at the mystery woman.
"Teacher Anna!?" exclaimed the Dragon, identifying the woman.
"So you remember me," said Anna, giving a heartfelt smile.
"Teacher?" asked Erza. The red-haired Fairy was curious; Wendy had never mentioned having a teacher before.
"Who cares who she is!?" interjected Jellal brusquely. His attention was on the more serious matter. "You say you know a way to defeat Acnologia?"
"We mustn't be hasty," responded Anna. "Everything must come in its proper order."
She took a moment to breath in and out, preparing to explain the rather complicated matter of her past.
"You see, I was the one who taught language and human culture to Wendy, Natsu, and the others, 400 years ago. Along with the dragon slayers, I traveled through the Eclipse Gate into this age. Into the year X777, all to defeat Acnologia."
"First Master, what do you think you're doing!?" yelled Natsu, his fists wrapped in fire. After arriving at the guild hall, Mavis had moved between him and Zeref to prevent them from fighting.
"Just give me a chance!" pleaded Mavis. "Let me talk to him!"
"…" Natsu hesitated, caught between the doubt that his brother could still be reasoned with and the knowledge that Mavis was closer to Zeref than anybody else. The Dragon remained silent, implicitly consenting by extinguishing the flames coating his hands.
As this exchange took place, Zeref walked over the Mavis and grabbed the Fairy by her hair, gripping it painfully tight.
"Zeref, hear me out," she said. The Black Mage did not respond. "I can save you. I can release you from your immortal life! I figured it out… the way to defeat you!"
"I already have a way," retorted Zeref, thinking about Neo Eclipse. "I'll reset time to prevent myself from ever receiving the Curse of Ankhseram! I can even kill Acnologia before he becomes the Black Dragon of the Apocalypse!"
With that proclamation, a pillar of light erupted from Mavis. The Fairy Tactician screamed as the power of Fairy Heart — already partially extracted by Irene — was forcibly torn from her body.
"First Master!" exclaimed Natsu, dashing toward the two cursed immortals to rescue Mavis. Zeref knocked the Dragon away with a blast of his magic, enhanced by the fraction of Fairy Heart that the Black Mage had already absorbed.
"Mavis," said Zeref, looking her in the eyes. "It's too bad that we'll never meet after Neo Eclipse activates, but… you'll probably live a much happier life… having never met me. Sorry, Mavis. I'm bidding farewell to this world!"
"You mustn't… erase this world…" said Mavis, forcing her screams down to speak. "This… world is… where I… met you… and our… son lived…"
The last of Fairy Heart drained from her body and into Zeref's, causing Mavis to faint. The Black Mage released his grip, causing her to fall to the ground. Natsu ran over to Mavis, shouting 'First Master' as he tried to shake her awake.
"She isn't dead," spoke Zeref, making Natsu pause. "But I have sucked all the magic out of her. I doubt she could even stand up now."
"You damn—" start Natsu, furious.
"The time has come," cut off the Black Mage, raising his arms. "This is… Fairy Heart!"
Infinite Magic Power surged within him, producing ripples that spread throughout Magnolia Town. They force was so intense that nobody in the guild hall, not even Zeref himself, noticed the single black wave mixed in that faded before it touched anyone.
As Anna's explanation came to a close, Wendy needed a moment to process everything that she had been told — the full story of July 7th, X777, Anna's relationship to Lucy, and the Space Between Time. Although she couldn't remember those events yet (which saddened the Fairy a bit), she could tell that what Anna said was true.
As Wendy calmed down, she overheard Jellal talking to Erza about the possibility that Anna was lying. The Dragon almost spoke up to dispel his fears, but Erza beat her to the punch.
"Anna!" shouted Ichiya, reentering the room. Having already heard the story, the Pegasus had left during it to check in on his guildmates. "We're approaching the indicated coordinates!"
"It's time, everyone!" announced Anna. "Grab onto something!"
"Barrel roll!" exclaimed Ichiya as Christina did a 360 degree spin to pass by the Space Between Time without touching it. If the airship did, then they would be trapped there forever instead of Acnologia.
"We've passed the Space Between Time!" declared Eve, currently operating Christina's information systems. "No damage to the ship!"
"Good!" responded Hibiki, pleased that his navigation was successful. He turned to Jenny. "Level the ship out."
"All that's left is for Acnologia to pass the same way, touch the Space Between Time, and vanish for good," stated Ren, still a bit tense as their plan reached its final stage.
The Black Dragon in question chased after them without stopping or moving to avoid the Space Between Time. And, when he came into contact with that space, a brilliant light exploded from it.
"Yes!" cheered everybody aboard the airship, which slowed down now that their goal had been achieved. Sadly, their rejoicing turned out to be premature.
Acnologia passed through the Space Between Time completely unaffected, catching up to Christina. The Black Dragon grabbed onto the airship's right wing with his arm, ensuring those onboard would not be able to escape.
As those onboard reacted to their plan's failure with disbelief, Anna scrambled toward the nearest window with a view of the Space Between Time.
"No," she whispered, horrified by what she saw. "The Space Between Time… It's closing up!"
Their only hope at stopping Acnologia was now gone.
As the Time Magic of the Space Between Time (which only the Black Mage could access, having sealed it off to all but himself) mixed with the endless power of Fairy Heart inside of Zeref's body, his appearance transformed. His body and clothes became pure white, with elaborate patterns decorating the latter. Wings of light extended from his back.
"First Master, we can't do it your way," muttered Natsu, looking at Mavis's unconscious body. "I've got to obliterate this guy!"
"You? Obliterate me?" asked Zeref in a condescending tone. "If you were capable of that, it wouldn't have come to this."
Natsu ran toward the Black Mage, entering his Pseudo-Dragon Force form (sans wings). Flames whirled around his right hand. "Fire Dragon King's Destruction Fist!"
Rather than burning, the effect of the Fairy's blazing punch was more akin to an explosion. It annihilated Zeref's body completely and still had enough power to blow a giant hole in the wall behind the Black Mage.
"It's been a few years since I wreck the guild hall like this," observed Natsu idly. He felt almost in shock, unable to believe that it was over so quick.
This disbelief proved to be more valid than the Dragon realized because, moments later, the destruction caused by his spell rewound itself. By the time it stopped, Zeref was completely unharmed and the guild hall no longer had a hole in it (though the damage prior to Natsu's latest spell remained).
"It's like… nothing ever happened…" went Natsu, stunned. The only evidence of his attack that the Fairy could detect was his own fatigue after using so much Magic Power at once.
"Space and time… everything is mine to control," stated Zeref as he walked up to his brother, who was still paralyzed by shock. A wisp of light came into existence around his right hand. "It is a limitless, eternal power. You could call it the pinnacle of all magic. A fitting power for the end of the world."
The Black Mage's hand punched through Natsu's chest without any resistance, causing the Fairy to cough up blood. Zeref removed his arm and walked past his brother, not looking back as the Dragon fell to the ground.
"Farewell, Natsu."
Had the Black Mage paused or turned around, he would have seen Natsu's scarf turn black as it absorbed a pulse of his death-inducing Curse. Instead, he walked forward to the guild's entrance.
"This world is over," spoke the Black Mage, calling upon the power of Fairy Heart. "A new one is about to begin. The doors to Fairy Tail… I shall make them the gateway to the new world. I need to connect the guild doors with the Space Between Time."
The doorway started to shine as it began connecting to the Space Between Time.
"The moment I pass through these doors… this world will crumble away… and my new world will take its place. The Fairy Tail doors have seen countless adventurers set out… and return home. And now these doors will be both the end and the beginning of worlds. Could the irony be any thicker?"
The doorway gave off a blindingly brilliant light. Neo Eclipse was now complete.
"I will retain my memories as they are as I go back to redo my life. And I will never make mistakes again. I shall save this world!"
Zeref walked toward the doorway.
Omake
Between Fairy Tail and their allies' final push and Ajeel calling for a ceasefire, it was not long before the fighting came to an end. Once that happened, a certain question inevitably rose.
"So, what exactly are we supposed to do now?" asked Gray a few minutes before Zeref claimed the power of Fairy Heart and the Space Between Time.
"Actually, I'm not really sure," replied Ajeel, a bit sheepish. "Zeref kept the specifics of how he planned to stop Acnologia secret, even from us Spriggan. But I'm sure that we'll known what to do when the time comes!"
"Great," said Gray, deadpan. "So we're just waiting until Natsu wins, then attacking Acnologia alongside him."
"Or Zeref," retorted the Spriggan. His words were a little heated, though he cooled down immediately. "But yes."
"…"
"…"
"…"
"Got any good stories?"
"A few."
AN: In case it wasn't clear, Blue Pegasus's attacks on Acnologia were just to make sure the Black Dragon kept following them. After all, if a Jupiter cannon and some heavy artillery were all it took to stop Acnologia, he wouldn't be so feared.
On a separate note, I'm kind of happy that Goku275 mentioned August. It gave me an excuse to bring up the minor resurgence of Zeref's Curse back in Chapter 78, something that happened again twice in this chapter (once due to Mavis and once due to Natsu). Thank you for that, Goku275.
That's all for now. Bye!