"W-what did you just say?"
Natsu's pupils shrank, while Happy trembled nervously in the air.
Zeref's calm voice cut through the tension.
"About four hundred years ago, our parents were burned alive by dragonfire… and my younger brother, Natsu, died that day."
Natsu's face twisted in confusion. "What the hell are you talking about?! First you say you're my brother, then you say I'm dead?!"
Zeref's eyes softened. "To bring you back, I devoted myself to the creation of life. And I succeeded. You were reborn as a demon of my own making—the strongest demon of the Book of Zeref. Etherious Natsu Dragneel. E.N.D."
Natsu's eyes went wide. The name E.N.D… he had heard it before, back when Tartaros attacked. And Igneel had told him himself that he failed to kill that demon.
"Me? END?!" Natsu shouted in disbelief. "That's impossible! If I were END, Igneel would have destroyed me back then!"
Zeref shook his head. "He couldn't. Not because he lacked the strength, but because he loved you. That bond stayed his hand."
"Shut up! END created Tartaros!! That's not me—I'm human!!"
Zeref lifted a book in his hands, the dark tome pulsing faintly.
"It was Mard Geer who created Tartaros, wielding this very book. He claimed to act in your name as END, but it was never you who led them."
He tossed the book to the ground.
"I SAID I'M NOT END!!!" Natsu roared, but Zeref casually extended a finger. A thin beam of darkness pierced the book.
"GUHHHHH!!!"
Natsu screamed as pain tore through his body, clutching his chest. Happy froze, horror dawning in his eyes.
"Natsu…"
Zeref's gaze was steady. "You never listened when I tried to teach you, never cared for words or writing. So I turned to my friend… Igneel."
At the name, Natsu's flames flared violently. "Don't you dare call him your friend!!"
"Igneel was different from most dragons—he wasn't hostile to humans. I met him while searching for herbs. He agreed to teach you Dragon Slayer magic, when he and Metalicana devised the plan of the Dragon Slayer children. They sealed their souls into your bodies with the Soul of the Dragon technique, then sent you to the future through the Eclipse Gate… all to slay Acnologia."
Natsu's breathing quickened as Zeref spoke, every word pressing down on him like a weight.
"You and the others—Gajeel, Wendy, Sting, Rogue—you are all children from four hundred years ago."
"Shut up!!!" Natsu charged, flames bursting wildly. His fist struck Zeref, hurling him back.
But Zeref stood once more, unfazed. "You are the demon of the Book of Zeref. If I die, you die as well."
"What?!"
Zeref continued, voice chillingly calm. "At first, I didn't understand why Su Yan spared me on Tenrou Island. But when he later begged me for your book in Tartaros… I realized he must know. If I'm killed, you vanish with me."
"Liar!! I won't believe a word of your nonsense!"
Zeref's expression faltered—just slightly. "…If you won't believe your brother… then believe your father."
Natsu froze. "What… did you just say?"
"Igneel never left you. He has been sealed within your body all along. Call to him, Natsu. Let him face Acnologia one last time."
The battlefield fell silent.
Then, from deep within Natsu, a weary voice rumbled out.
"...Alas."
It wasn't Natsu's voice at all. It was Igneel.