"Demon Slayer" Final Climax: Tanjiro Turns into a Demon! Why Does He Become the Strongest Demon King? How Does He Return to Being Human?

Preface: The Gentle Hero's Most Desperate Transformation

The story of "Demon Slayer" begins with a tragedy, as Tanjiro embarks on a journey to restore his sister, who has turned into a demon, back to human. However, in the final battle of the manga, it takes the most heartbreaking turn—Tanjiro, who should have been the demon-slaying hero, becomes a demon himself, and moreover, the "Demon King" who surpasses all other demons. This plot point is not only the climax of the story but also brings the ultimate test to the core themes of "bonds" and "humanity." This article will provide an in-depth analysis of the causes and consequences of Tanjiro's demonization and how he ultimately escapes this nightmare.

Reason for Demonization: The Final Curse of the Progenitor of Demons

In the final battle against the Demon Slayer Corps, the Progenitor of Demons, Muzan Kibutsuji, is driven into a corner and gradually turns to ashes under the morning sun. However, before his complete annihilation, he injects all his remaining power and blood into Tanjiro, who is severely injured, near death, and whose heart has stopped.

Muzan's goal is very clear: he wants to entrust his will and his dream of creating the perfect being to this youth who has inherited the Sun Breathing. He attempts to make Tanjiro his vessel, a new "ultimate being" capable of overcoming sunlight, thereby ensuring his own eternal existence and fulfilling his long-cherished wish to annihilate the Demon Slayer Corps.

The Birth of the Strongest Demon King in History: The Sunlight-Overcoming Demon

After turning into a demon, Tanjiro's abilities far surpass those of any previous demon, making him the strongest Demon King in history.

• Overcoming Sunlight: Like his sister Nezuko, the demonized Tanjiro completely overcomes the demons' most fatal weakness—sunlight—and can stand unscathed in broad daylight.
• Hyper-Regeneration: The left arm and right eye lost in battle instantly regenerate after demonization, with a regeneration speed that even surpasses that of the Upper Moons and Muzan himself.
• Uncontrolled Aggression: Having inherited Muzan's will, Tanjiro completely loses his sanity and launches indiscriminate attacks on his former comrades, his eyes becoming as cold as a snake's.
• Blood Demon Art: Like Muzan, Tanjiro can extend sharp bone whips from his back to attack, demonstrating immense destructive power.

This sudden transformation plunges the already exhausted Demon Slayer Corps into unprecedented despair.

The Victory of Bonds: How Did Everyone Pull Him Back to the Human World?

Tanjiro's demonization becomes the cruelest test for all members of the Demon Slayer Corps. Facing their former dear friend, no one can bring themselves to kill him. Giyu Tomioka hesitates, Inosuke cries uncontrollably and cannot swing his sword, and his sister Nezuko, who has just turned back into a human, desperately hugs her demonized brother, trying to awaken him with familial love.

At this desperate moment, Kanao Tsuyuri becomes the key savior. She takes out the last remaining dose of the "medicine to turn back into a human," jointly developed by Shinobu Kocho and Tamayo. To successfully inject the medicine into Tanjiro, Kanao risks blindness by using the Final Form of Flower Breathing, "Equinoctial Vermilion Eye," once again, barely managing to complete the task.

As the medicine takes effect, the calls of his companions and his sister's protection successfully reach Tanjiro's spiritual world, helping him resist Muzan's will within him. Ultimately, through everyone's efforts, Tanjiro successfully breaks free from Muzan's control and turns back from a demon into a human.

Conclusion: The Cost After Demonization and the Arrival of Peace

Although Tanjiro successfully turns back into a human and the world welcomes a peace without demons, the battle still leaves indelible scars. His left arm and right eye, which had regenerated, although restored in appearance, lose all function and become withered.

Tanjiro's demonization is the most dramatic chapter in the conclusion of "Demon Slayer." It not only allows the protagonist to personally experience the pain of becoming a demon but also inversely proves that human will and the bonds between companions can ultimately overcome the deepest resentment and curses. Although a heavy price was paid, Tanjiro eventually returns to his hometown with his sister and companions, living a peaceful and happy life, drawing a gentle and profound conclusion to this long demon-slaying story.

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