Disclaimer: I don't own anything, especially not Merlin.
It was like a scene from a nightmare, a vision of hell. Screams rang through the air as swords clashed, shields fell, and men died. Bodies lay on ground stained red with blood. The armies clashed and it seemed as if the end would never come. Two banners stood beneath the tumultuous sky. The first a field of black with a crimson tree and the second was a golden dragon resting on a red sky.
Beneath the dragon's banner, a tall and pale man surveyed the battle with eyes of blue steel. All of his senses were searching for the one he was born to protect: his king, his master, his friend. Magic crackled around him like barely contained lightning, tense and ready to fulfill its purpose.
Finally, he saw him. Arthur was in the center of the battle like always, fighting off a group of soldiers. Excalibur gleamed as it struck down man after man until no more stood against its master. Merlin smiled proudly at Arthur's prowess and Arthur grinned back as his friend approached. He opened his mouth to say something, but the words never left his lips. Shock overtook Arthur's face as he looked down at his chest and saw the sword tip sticking out of it.
Merlin's world froze as he took in the scene before him. He heard screaming, but it wasn't until he was running toward Arthur that he realized that it was his screams he was hearing. Arthur glanced back up toward Merlin before his body fell to the ground, revealing the grinning Mordred behind him. No longer was he the innocent, silent child who the prince had helped escape. He had grown into a man, into a sorcerer who had fully embraced his destiny and had murdered the king, Albion's greatest hope.
When Merlin's mind registered what Mordred had done, his magic roared through his veins and broke free of all restraints Merlin had. Waves of golden power surrounded the enraged warlock, obliterating any enemy they encountered. Mordred brought up a shield to block the brunt of the waves, but could not escape the warlock himself. Merlin's eyes blazed with pure gold as he whipped an arc of fire at Mordred, surrounding him in a cocoon of flame.
Merlin remained unaffected as Mordred's screams and pleas for mercy filled the air.
"Why should I grant you mercy when you have taken such a great king from the world? Why should I let you live when, because of you, my friend is dead?" Merlin's voice coldly asked the dying man. "You will suffer and then you will die, and no one will live to mourn your passing." Merlin raised a hand toward the makeshift pyre, lips forming words of the Old Religion. When he finished, the flames receded from Mordred, still alive yet unable to move, and formed a dragon made of pure fire. The beast roared, its cry filling the air with rage and sorrow, and flew toward the helpless sorcerer. It engulfed him its jaws and ended Mordred's life with an explosion of power.
Merlin lowered his shaking hand as he turned away from the fire and toward the body of his friend. Arthur lay on the ground in a pool of his own blood, his chest barely moving. Running forward and falling to the ground next to Arthur, Merlin took him into his arms and surveyed the wound.
"You can't heal it. You know you can't." Arthur whispered, blood trickling from his mouth.
"There must be something I can do." Merlin all but screamed as he tried spell after spell in an attempt to stop the flow.
"Merlin, you idiot, not even you can stop death. It's time. I'm just glad that you're here with me in the end." Arthur's eyes were fixed on Merlin's face, even as his eyelids began to droop.
"Arthur I'm sorry. I'm so sorry. I should have seen him. I should have stopped him." Merlin cried as tears streamed down his face. "It was my destiny to protect you and I failed." Arthur lifted a hand to his friend's face.
"Merlin you fulfilled your destiny and you did even better: you gave me your friendship. I would not be the man I am today without you. You are the selfless and courageous man I have ever met and I am honored to have been your friend." Arthur's coughing began to worsen, the blood flowing at a quicker pace. Commanding the final bit of his strength, Arthur spoke his final words with a grin. "Goodbye Merlin. I'll meet you again in Avalon. I'll be needing a servant there when you arrive." The light began to leave his eyes and in moments Arthur Pendragon, the Once and Future King, had died.
The moment Arthur's heart stopped, Merlin's magic spun out of control. His body remained crouched over his friend, shaking with the force of his sobs, as the magic tore across the battle field one last time. Storm clouds thundered in the sky, pouring down rain, while the earth shuddered violently. Soldiers from both armies fled in terror and golden magic lashed out at anything that remained. And then suddenly, there was silence.
A few brave knights, those who had sat at the Round table, searched through the rubble to find their king and his warlock. Finally, Gwaine's shout brought them together at their goal. The two bodies were completely undisturbed by the chaos, Merlin resting over Arthur's prone form. Gwaine stepped forward to check their pulses, and then fell to his knees with a cry when he found none. The rest of the knights gazed at the pair in shock, as if unable to comprehend what lay before them.
The faces of both men were serene and at peace, despite the horrible circumstances of their ends. The king had died with his greatest friend at his side, having done his best for his kingdom. The warlock had died alongside his king, following his friend as always, even into the afterlife.
For a half cannot live without that which makes it whole.
