Tanjiro is a damn good protagonist! But how would he fare as a villain, especially
if he’s in the upper ranks of the twelve Kizuki? We are here once again, to satisfy your thirst
for fan theories, but not without including an unbelievable twist, so stay tuned. On a fateful cold morning, Tanjiro climbs
up Mount Kumotori before the sun rises, in hopes of seeing his family after a long day
of selling charcoal and spending the night in a shack at the foot of the mountains. As he opens the door of his house, he finds
it empty. He enters the room, announcing his arrival,
but no one replies. Getting more suspicious by every passing second,
he decides to look for them in the main hall. As he opens the door, he finds his family
bloodied in a pile, with Muzan standing next to them. He notices that Nezuko is still alive and
being held by Muzan. As soon as Muzan notices Tanjiro, a chill
climbs up his spine as he recalls the memory of a similar man who almost killed him many
decades ago. He pumps Nezuko with the excess of his blood
and throws her in a corner. As soon as Nezuko hits the floor, Tanjiro
rushes towards her in order to help. Although Muzan is dead afraid of Tanjiro and
is uncertain of any hidden ability he might possess, he announces that the girl won’t
be alive for long and that he should say his goodbyes while he has the chance. Nezuko, in the arms of Tanjiro, utters her
last words, stating that she couldn’t protect her family, and dies as her head explodes
from excessive inflammation. Muzan realises that Tanjiro isn’t a threat
and laughs at Tanjiro’s predicament, addressing him as a weakling. Tanjiro picks up his axe in a fit of rage
and dashes towards Muzan to punish him for what he did to his family. Muzan, however, gives off a smirk, and grabs
Tanjiro by the throat, stating that he has no use for him. Tanjiro repeatedly shouts at Muzan, threatening
to end him, but he soon loses consciousness. Muzan exclaims; "What a fool! To be daring enough to threaten the demon
king." As Muzan releases Tanjiro, he notices that
Tanjiro actually managed to stab him in the side. Impressed by the boy’s conviction, he waits
for him to gain consciousness and proposes a deal to him. Muzan states that if he becomes a demon and
serves under him, he might bring his family back to life as a reward. A grief-stricken Tanjiro is desperate to find
meaning after the sudden shock of his family’s demise, and actually considers Muzan’s preposition. Muzan whispers in his ears, that remaining
alive as a human will no longer be worth the effort without his family by his side. But although Muzan looks sincere on the outside,
he’s still unsure of Tanjiro due to his connection with the mysterious swordsman who
almost ended his life several years ago. Muzan is ready to kill Tanjiro if he refuses
to convert, however, due to the drowning sorrow in his heart, Tanjiro agrees to become a demon. Muzan gives off a vicious grin and proceeds
to inject him with a substantial amount of his blood. Tanjiro falls flat on the floor and gives
off painful groans due to the process of him turning into a demon. After several minutes of intense pain, Tanjiro
rises. His eyes turn black. Scarlet horns spike out of the side of his
forehead, and he summons a flame like mark on his head. As, Tanjiro’s transformation is complete,
he smells an intruder in his home. Suddenly, Giyu arrives at the scene and unsheathes
his sword as he spots Tanjiro. As his eyes wander around, he notices a well-dressed
man standing beside Tanjiro. Giyu’s eyes light up with fear, and he almost
loses the grip of his sword as he realises that the man is Muzan Kibutsuji, the demon
king himself. Muzan states that this is a good time for
Tanjiro to prove his loyalty by finishing up the demon slayer scum. Tanjiro focuses on Giyu and lets off a fiery
breath as he rushes towards the Hashira. Giyu tries to calm down, as he knows that
he cannot take on Muzan, but he’s also confused as he doesn’t know what Tanjiro is capable
of. Giyu tries to play his trump card and use
the eleventh form to finish the fight quickly, but Tanjiro jumps over him at the last second
and claws his head off. Upon the sight of blood, Tanjiro starts salivating
and rushes to his knees to gnaw on the corpse of a person who could have been a trusted
comrade in another life. Everything is going just fine for the demon
king, except for one frustrating fact. He hasn’t gained control over Tanjiro’s
mind yet and is still detached. After Giyu’s corpse is no more than a ruined
piece of meat, Tanjiro demands that Muzan resurrect his family, as he has proven his
loyalty to him. Muzan explains that it isn’t possible for
him to instantly resurrect dead people and that it would take a lot of time to make the
preparations.Tanjiro turns away and storms off, stating that he’ll be back when he’s
ready. Muzan has mixed feelings about what just happened. He’s happy that he turned a potential threat
into an asset, but he has no control over that asset right now. Muzan lets Tanjiro go as he thinks it’s
the best outcome until he figures out his next move and sees how the slayers react to
a hashira dying. Meanwhile, in the demon slayer corps, Kagaya
is struck with grief due to the news of Giyu’s death, while all the hashiras have opinions
of their own. Kagaya proclaims that a substantial change
has been triggered in the environment, one that does not seem to be favouring them at
the moment. Kagaya dismisses the Hashiras and explains
to his wife that he had a vision, where a demon gained the ability to walk in sunlight,
and he suspects that the strength clearly indicates that it was Muzan. Several months later, two more Hashiras fell
in battle. Rengoku is killed by Akaza, and Tengen succumbs
to Gyutaro’s poison but is able to take the siblings down. Meanwhile, Tanjiro roams around the island
of Japan and takes refuge in a cave one morning. Tanjiro is different from other demons as
his memories from his previous life are still strong, and tug at his heart every day. Tanjiro decides that this nomadic life, which
involves eating his own kind and spreading malice, is not worth living. He decides to unalive himself by walking out
into the sunlight. As the rays of the sun hit Tanjiro’s face,
it starts burning, and Tanjiro reminisces about the good times he had with his family
one last time as his body began succumbing to the sun's rays. As Tanjiro’s skin is completely burned off,
it suddenly starts regenerating, which shocks him. Tanjiro realises that he’s achieved the
highest form of being and that he’s invincible now. However, Tanjiro’s starts getting visions
of his ancestors telling him that what he has achieved is nothing but eternal misery. This sound echoes for hours in Tanjiro’s
mind as he lays in his cave thinking about his next move. A realisation hits Tanjiro that the power
of eternal life could prove devastating in the greedy hands of Muzan. He remembers that Muzan did mention the slayers
and how they've been at his tail for decades. Meanwhile, Muzan gains information about Tanjiro
achieving immortality and his plan to contact the slayers through Nakime’s eyes. He hatches a plan that would kill two birds
with one stone. He plans to allow Tanjiro to track down Kagaya
using his nose and then attack the corps, ending them once and for all. He’ll then absorb Tanjiro to gain immortality,
which will complete his centuries old quest. Tanjiro, starts tracking the demon slayers
all around Japan to get an idea of their bases and where they’re located. He soon finds out about the swordsmith village
and decides to visit it in the hopes of finding someone who could help him there. However, while he’s running loops of the
village, he runs into Gyokko, the upper moon five. Gyokko comes out of his pot and greets Tanjiro,
not knowing that he has attained immunity from the sun or that he’s about to betray
them. Suddenly, Hantengu shows up as well and asks
Gyokko to be merciful to him as he’s their precious kouhai. The tension rises in the atmosphere as Tanjiro
doesn’t utter a single word. Tanjiro tries to turn and walk away, but he
suddenly turns back and attacks Hantengu, severing his head, and causing a big blast. A fierce battle erupts between the three,
which alerts Mitsuri, Genya, and Muichiro, who are currently in the village. They go on to confront the demons, but are
perplexed to see two demons fighting another demon. They are indecisive about whom to support,
but Mitsuri states that the two demons have numbers engraved in their eyes, which means
they’re upper moons. The three of them side with Tanjiro and overpower
the upper moons, killing them for good. In the end, the three of them surround Tanjiro,
demanding an explanation. Tanjiro explains his situation, and the three
slayers decide to let Tanjiro prove his conditions by staying out in the sun. Tanjiro verifies his immunity, and Mitsuri
promises Tanjiro an audience with Kagaya. They all travel back to the demon slayer headquarters,
where Kagaya is already waiting for them with other Hashiras, citing that the time is now. Kagaya explains that Muzan is soon going to
attack their base as he has tracked Tanjiro, and they can kill him if they plan the ambush
well, using Tanjiro as bait. After hours of waiting, Muzan arrives and
finds Tanjiro waiting for him in Kagaya’s room. Suddenly, traps go off, Muzan gets surrounded
with blasts, and Tanjiro escapes while all the Hashiras rush towards him to cut off his
head. Muzan, gives off a smirk, as the three upper
moons arrive at the scene to defend him. A brutal battle erupts, and Muzan tries to
chase down Tanjiro. With the help of Nakime, he is able to locate
Tanjiro nearby, and the final battle begins. While fighting Muzan, Tanjiro is pushed to
the brink, and his strength starts growing with every hit Muzan inflicts on him. Muzan finally captures Tanjiro, and states
that he’s immortal now. But as it penetrates Tanjiro’s chest to
absorb him, a fire engulfs his arm and burns it off completely. Tanjiro manifests his blood demon art, which
is overpowered even for muzan. He starts using the fire to fend off Muzan,
stating that he just needs to stall him till daybreak. Suddenly, Muzan lets his tentacles loose and
starts using them like whips to hurt Tanjiro. However, suddenly, one of his whips gets cut,
and it is revealed that the slayers put down the upper moons but incurred heavy losses
in the form of a number of hashiras and other slayers. Muzan isn’t able to believe that this is
how his life is going to end. He shouts out like a maniac and summons every
ounce of strength to kill every surviving member, but his efforts are to no avail as
the sun is almost on the horizon. He tries to wrap himself in a cocoon and dig
through the dirt, but Tanjiro burns off his upper flesh to let the sunrays fall directly
onto Muzan. Thus, the life of the demon king comes to
an end, due to the very demon that he created to extend it. THE END?
