Finally. After all this time, I've found him, Gray thought, running through the trees laying on the edge of a small village. After a year of searching, he had finally found the location of END. And now I can destroy him. Whatever this demon was, regardless of him being Zeref's strongest demon, he would kill it. He won't get away from me this time.

After Zeref had disappeared with the book of END, Gray had been searching tirelessly for it. During his search about three months before, he heard rumors of one of Zeref's demons appearing in a small coastal village. This village. The only one of Zeref's demons left is END, so it must be him.

After a year, it was finally time.

As he made his way into the village, a strange sense of familiarity washed over him, setting his nerves on edge. He had never been to this village before, so what was this feeling? Something familiar was here, but he couldn't tell what it was.

"Hey, old man," Gray said, approaching a merchant along the street.

"What can I do for you?" He asked, smiling.

"I'm looking for a demon," Gray told him. "I heard he was spotted around here. His name is END."

"You mean that fire demon," the old man answered, fear clear on his wrinkled face. "That devil nearly destroyed the village just up the coast from ours. If you're looking for him, I'd head North. He hasn't made it this far South, but rumors say he's on his way."

"Thanks," Gray nodded. Wasting no time, he took off in the direction the old man had instructed. As he passed through another small forest, that feeling of familiarity came over him again. The smell of smoke quickly distracted him from that, however, and he ran a little faster. It must be him!

As he came out of the forest, a ball of fire came crashing towards him. "Ice Make: Shield!" He shouted, throwing the wall of ice up just in time. It exploded in a cloud of steam as the fire hit it, throwing him backwards. "Damn," he grumbled, getting to his feet.

When he finally spotted the demon he had made an oath to kill, his entire body froze. No. The thought played through his mind like a track on repeat. It can't be…this has to be a mistake. END...END is—

"Fire Dragon's Roar!"

The most Gray could do in his shocked state was throw his arms in front of his face to block most of the attack. This time when he hit the ground, the air left his lungs in a loud oof and he found himself staring at the blue, cloudless sky. Before he could catch his breath and sit up, a figure appeared above him, blocking out the sky and casting a shadow over him.

"Hello, Gray."

"Natsu." It was barely a whisper as he gazed up at his oldest friend. Natsu's onyx eyes were now a deep red, and crimson scales covered each side of his neck and face, disappearing into his hairline. At the top of his head sat two horns, as black as the night sky.

A wicked grin spilt his lips as he crouched down to snicker at Gray. "Long time no see, friend."

"Natsu, what the hell is going on?" Gray snapped, jumping to his feet.

"I think you know exactly what is going on," Natsu smirked, coming closer. Reaching up, he ran a clawed finger down the side of Gray's face. "You've matured in the year we were apart. Your training certainly has paid off." To that, Gray took a step back. Malice radiated off Natsu in waves, once again setting Gray's nerves on edge.

"Are you telling me you're END?" He asked, silently praying Natsu would deny it.

"In all that time researching the book of END, you're saying you never found out what it stands for?" Natsu asked.

"It didn't matter what it meant," he frowned, "I'm going to kill the demon known as END, so I don't care about its name."

"It stands," Natsu said, closing the distance between them again, his lips so close to Gray's ear that he could feel his breath, "for Etherios. Natsu. Dragneel."

For the second time, Gray was frozen in shock. Natsu pulled away, cackling madly at Gray's reaction. "I am END, Gray! The demon you've been searching for all this time is standing right in front of you. So, what will you do now?" Slowly, Natsu circled him, that wicked grin never leaving his face. "Will you kill me, Gray? Your best friend? The man you love? Will you kill me? Because I," he stopped, once again directly in front of Gray, "I don't think you can do it."

"No," Gray shook his head, reminding himself why he was there. He ignored what Natsu had said about loving him, having banished those feelings as soon as he had sworn to destroy END. "You aren't Natsu," he said. "You might have once been him, but you aren't anymore. And I know if the real Natsu was in there, he'd want me to take your ass down."

"You're such a fool," he sighed, sounding amused. "I am Natsu. Natsu has always been me. I have just been dwelling within him, sleeping, until someone finally woke me up. And six months ago, Master Zeref finally did. And now—Ah!" Natsu winced, one of his hands going to his temple, as if he'd suddenly had a sharp pain. "Damn you," he growled, quietly, to himself.

Using the distraction, Gray took the opportunity to attack. I have to finish him quickly. Honestly, he didn't think he could bring himself to fight against Natsu for very long—even if END wasn't the Natsu he grew up with. "Ice Devil's Rage!" He had only ever used the attack once before while fighting Mard Geer of Tartarus, so the breath attack felt so foreign to him. Yet, he had been training with it for so long that he was confident it would do the job. Natsu, I'm sorry.

Natsu looked up just as the ice hit him. Instead of sending him flying, the ice enveloped him, locking him in its inescapable prison. Gray approached the ice, a secret, selfish side of himself hoping that Natsu was still alright, that he had gone back to normal when the demon slayer magic had hit him.

A few feet from Natsu, Gray stopped, hearing a strange noise coming from inside the ice. That sounds like something is sizzling, he thought, frowning. He gasped when the ice suddenly began cracking, and soon shattered, large chucks being thrown several feet away.

"That wasn't very nice, Gray."

"H-How?" He couldn't believe it. My attack hit him, so how is he still alive?! What was more, apart from a small graze on his cheek, he seemed completely unharmed.

"I'm not as weak as that dragon slayer," Natsu chuckled. "The smile quickly fell from his face when he met Gray's eyes. "But you have succeeded in pissing me off. I think I'm done playing with you now. If you won't fight fair, I'll just kill you." He shot forward, his clawed fingers coming together to form a point as fire engulfed his hand.

"Ice Devil's—" Gray's attack fell short when Natsu suddenly came to a stop, his hand mere inches from Gray's chest.

"St-Stop it," he growled, shaking his head. His free hand went to his temple again, and Gray watched in confusion as he took a step back, closing his eyes. "Get…out."

It was then that Gray realized what was going on. Natsu. He must be fighting against END. "Natsu…" Gray said, willing his voice to reach his friend.

"G-Gray…" Natu's voice sounded strained, and sweat was beginning to glisten on his forehead as he opened his eyes. They were no longer red, but the onyx that Gray had grown so fond of. "Gray, you have to…stop him. Stop END."

"How can I do that?" Gray snapped. "You're END!"

"I know that!" He met Gray's eyes, the red in his own slowly coming back, swirling around his dark irises like an eerie smoke. "He—I—have hurt so many people. Lucy…and Happy." Tears rolled down his cheeks, sliding over the crimson scales on their way to the ground.

Dread settled in Gray's gut, making him feel sick at the implications of Natsu's words. "But you're still—"

"I can't control it, Gray!" He bit out, grabbing the front of Gray's shirt with both fists. "I'm not going to be in there for much longer. And once I'm gone," he took a deep breath, "once I'm gone, END is going to hurt a lot of people. You have to stop him before he can."

"I can't kill you," Gray said. It was difficult to speak now passed the lump in his throat. "I thought I would be strong enough, but I'm not. Not to kill you."

"You have to." Natsu's voice was pleading. "Don't let your feelings get in the way of what's right! You have to kill me. I'm going to disappear anyways, so don't you think I'd rather go out now, instead of when END has completely erased me?"

Gray blinked away tears, nodding. "Natsu, I—"

"AAHH!" He doubled over, both hands covering his face as he cried out in pain. "Gray! Do it now!"

"Natsu—"

"DO IT!"

"Ice Devil's Zeroth Long Sword," Gray said, clutching the handle of the sword as it materialized. Before he could change his mind, he thrust the sword down, plunging it into Natsu's chest.

"Damn…you." Nothing but red eyes full of malice and hatred met his as Natsu fell back, his entire body slowly crystalizing.

After Natsu fell, Gray sank to his knees beside his friend, the tears running freely down his face now. He had trained and prepared for a year, but he hadn't been ready for this. No amount of time could have prepared him to kill his best friend.

No amount of time could have prepared him to kill the man he loved.

"G-Gray." It wasn't even a whisper, but Gray had heard it. He looked up, finding himself meeting onyx eyes. Natsu smiled at him in the toothy way he always used to. "Thank you."

"Natsu…"

"Bring—Bring Fairy Tail back together. Bring…our Nakama…back together." With those words, the ice had spread to his face, and his body turned completely to ice.

Gray stayed there, silent, until Natsu's frozen body crumbled and blew away, leaving behind no traces of the former dragon slayer, nor of the demon he had become. Once he could no longer bring himself to sit there any longer, Gray got to his feet.

"I'll bring them back, Natsu. This won't be the end of Fairy Tail."