From the start of Demon Slayer, we are shown
that becoming a demon is basically THE. MOST. HORRIFIC. THING that can happen to a human. Because even though they gain super strength,
speed, and healing, demons lose every bit of their humanity. So when Rengoku rejected the chance to become
a demon during the Mugen train arc, he showed us that he would rather DIE than become a
demon. But what if Rengoku had decided to live on
and continue fighting as a demon? So let’s rewind. Akaza punches a hole through Rengoku’s stomach
and once again offers to turn him into a demon. With Tanjiro screaming in the background,
Rengoku realizes he is going to die. In the original story, Rengoku accepted his
fate with open arms, but let's imagine for a moment that Rengoku shows some vulnerability
and doesn’t want to die. Perhaps he clings onto life with every fiber
of his being, refusing to accept his inevitable fate. Or maybe he is determined to continue his
fight against demons and is willing to undergo the ultimate and painful sacrifice to gain
the power to do so. And so this time, Rengoku accepts Akaza’s
offer. With a wicked smile, Akaza infuses Rengoku
with enough of the demon king’s blood to start his transformation into a demon. And while this agonizing process begins, the
sun begins to rise. With his last moments of sanity, Rengoku promises
Tanjiro and the others that he will come back one day to fight by their side. As the sun rises, Akaza mocks this promise
and then carries Rengoku into the safety of the dark forest. Now, we know from later on in the manga that
super powerful humans like the Hashira can take a few days to fully transform into demons. So Akaza takes Rengoku somewhere safe and
isolated during this transformation. Maybe a dark cave or abandoned house somewhere. However, since Akaza selfishly wanted Rengoku
to be his own personal fighting partner, let’s assume that he does not take Rengoku back
to the demon king, Muzan, and instead keeps him far enough away that Muzan remains unaware
of Rengoku’s transformation for now. So a few days pass, and the newly formed demon
Rengoku awakens. His body has dramatically transformed with
razor-sharp spikes, terrifying horns, and swirling flame patterns along his skin. And like any new demon, the first thing he
craves is food. And now the possibilities of this insane what
if scenario can branch in many different directions. You see, we already know that demons will
sometimes lose their human memories after the transition. So it is possible that Rengoku could completely
forget who he was and become a ruthless evil demon who eventually serves Muzan. However, some demons do keep their memories,
or eventually recover them over time, so let’s assume that Rengoku’s crazy strength and
will enables him to hold onto some of his humanity, despite his new demon form. But the cravings that come with his new demonic
form begin to drive him insane. The hunger eats at his insides, and his body
grows weaker by the hour. But Rengoku refuses to give in to his demon
desires and he refuses to eat anything that Akaza brings him. Now Akaza, who thinks that humans are pitiful
and weak, grows increasingly enraged by Rengoku’s defiance. The air crackles with tension as both Rengoku
and Akaza find themselves eager to fight. Rengoku desires nothing more than to kill
Akaza for revenge, while the other demon is determined to beat the humanity out of this
new, super strong adversary. So they clash, with Rengoku using a brand
new blade of black flames made from his blood demon art. But despite gaining the usual supernatural
strength, speed, and healing of a demon, Rengoku struggles to keep up with Akaza's full power,
which he never displayed during the Mugen train incident. Rengoku fiercely fights against his demonic
cravings for days as Akaza tempts him with human flesh. The two demons battle each night, and Rengoku's
will to hold onto his humanity weakens. Akaza warns him that Muzan will kill him if
even thinks about betraying the demons, and Rengoku knows he can't hide his intentions
from Muzan's mind-reading powers. There is literally nothing Rengoku can do. Except for one thing. Rengoku grows weak from hunger and decides
to end his existence as a demon by stepping out into the sunlight. But just before he can, Akaza tempts him with
more food, and this time, Rengoku’s failing spirit snaps. As he indulges his demonic needs, his human
memories fade. They are locked deep within his min and he
eats in order to stay alive. Rengoku’s transformation into a demon is
complete. And now let’s shift to the Demon Slayer
Corps, where Rengoku's betrayal leaves the group devastated. And there are many ways that the Demon Slayers
could approach the situation, but no matter what the loss of one of their strongest warriors
is a terrible blow, made all the worse by the knowledge that he now serves their greatest
enemy. It is likely that Rengoku's father would commit
seppuku in shame. And we have to imagine that the rest of the
Demon slayers are in chaos. Because from the manga we know that one of
Muzan’s eventual goals is to find the Demon Slayers’s base and wipe them out. Since Rengoku knows where the mansion is,
Kagaya Ubuyashiki, the leader of the demon slayers, could be incredibly worried about
Muzan learning this information and he could consider a few options. Such as ordering everyone to leave and set
up a new base somewhere else. Or he may simply think that strengthening
their current base is the best option because it is basically already the most demon proof
area in the world. But let’s assume that for now they choose
to stay, and they have an intense debate about what to do regarding Rengoku. Some of the Hashira, like Sanemi, the wind
Hashira, and Giyu, the water Hashira, could demand they hunt him down for his betrayal. Others, like Tanjiro and maybe Gyomei, the
stone Hashira, could argue that they need to talk with Rengoku to see if they could
bring him back to their side. And Tanjiro is extremely concerned about what
would happen when the Demon Slayers eventually confront Rengoku again. So keep watching to see how this epic clash
turns out later in the video. But before the group separates for their next
missions, I definitely think Tanjiro would ask permission to go see Lady Tamayo, the
demon who is working on a cure to turn demons back into people, to see if she has made progress
on the life-changing medicine. But it still probably wouldn’t be ready,
so Tanjiro vows to continue to send her demon blood to help with the research. And with Rengoku now a fully fledged demon,
Akaza would definitely take him to meet Muzan. And wow is the demon king furious with Akaza
for making Rengoku a demon without his permission. It is entirely possible that Muzan could obliterate
both of them on the spot, fearing that Regnoku may eventually betray him or become too powerful
to control. But for now let’s assume that he restrains
himself because he recognizes the opportunity to gather more intel about the Demon Slayer
Corps. Muzan attempts to read Rengoku's mind, but
he is incredibly disappointed that Rengoku has lost all of those memories. For now. Once more, Muzan’s temper ignites, but he
spares Rengoku’s life for a reason we will see later in the video. Because Rengoku was already super strong as
a human, I think Muzan would make him Lower Moon 1 since that spot is now empty after
the Mugen train battle. Then Rengoku is sent out into the world. And this is where this story gets pretty dark. At this point, the demon Rengoku would be
hungry for power and would likely become a terror in the human world. He buries his human shame and guilt is deep
alongside his memories. His dark flames consume everything in their
path as he rampages through villages. And this takes us to the events of the entertainment
district arc, which we saw in season 2 of the anime. During this arc, Tanjiro and the others team
up with the Sound Hashira, Tengen, and his wives to take out the Upper Moon 6 demons
Daki and Gyutaro. And I think these events would progres pretty
much as they did in the original story. Tanjiro and the others investigate and eventually
uncover Daki’s presence. They clash in these epic battles. Daki is almost killed until Gyutaro reveals
himself. And just like in the original, Daki’s ability
to use her cloth as a weapon and Gyutaro’s poisonous blades almost wipe out the Demon
Slayers. But eventually, Nezuko awakens her next demon
form, and in the end, the Demon Slayers are victorious. Though badly injured, the main characters
are still alive, and Tanjiro even briefly awakened his demon slayer mark during the
fighting. But now Rengoku enters the fight. You see, after all this time attacking humans
and even practicing against Akaza, Rengoku has grown extremely powerful. Much stronger than the Upper Moon 6 demons
who were just defeated. And so it is the perfect opportunity for Rengoku
to defeat the Demon Slayers and claim Daki and Gyutaro’s place within the Upper Moons. And this is a truly awful time for the slayers’
first confrontation with Rengoku. Nezuko is recovering from nearly going Berserk. Tengen and Inosuke are hanging on by a thread. Tanjiro and Zenitsu are completely spent. But none of that matters to the demon Rengoku. His black flames begin to consume the town
and burn the people inside. Exhausted, Tanjiro stands up, wielding his
chipped blade, and confronts this new demon, but he nearly drops the sword when he recognizes
who has arrived. In utter disbelief, Tanjiro stands frozen,
gazing upon the terrifying demonic form of Rengoku. Despite his shock, I still think Tanjiro would
want to talk to Rengoku. That is after all Tanjiro’s main character
trait, that he always believes in a person’s capacity to be good. So Tanjiro frantically calls out to Rengoku’s,
begging him to stop the destruction. But Rengoku barely pays him any attention. Instead, he heads straight for Tengen, who
is writhing in pain due to the poison still in his blood. Looking down on the Sound Hashira, Rengoku’s
flames flare. And this might stir memories and guilt within
him, but demon Rengoku is focused on his goals and pushes them back down. He raises his burning sword, then swipes down
at Tengen. Tanjiro leaps forward, raising his sword to
block the killing blow, but the force of the blow throws Tanjiro aside. Tengen is helpless, and the slash slices through
the Sound Hashira. And with one demon slayer dead, this is where
the battle would really heat up. So as we’ve seen with every other demon
Tanjiro has faced, his rage comes spilling out. Rengoku turns his dark, soulless eyes on the
young Demon Slayer. Tanjiro shouts at his former friend, demanding
that he remember himself. Rengoku loved people. He wanted nothing more than to protect humans
from demons. But the demon Rengoku barely reacts. Instead, he approaches Tanjiro. With unwavering courage, Zenitsu and Inosuke
stand beside Tanjiro, even though they can barely move, and together they face down their
most terrifying threat yet. A former friend turned into a heartless monster. They clash, but the three of them are definitely
no match for the demon, especially because they were pushed to the limit in the previous
battle. Even Nezuko joins the battle, but she is also
exhausted. So Rengoku traps them in a burning cage of
black flames, and with no shred of humanity in his eyes, he raises his blade to strike
them down. Then, the wind picks up. The flames flicker. And suddenly, the fire is gone. And Rengoku vanishes. At least as far as the three young demon slayers
can tell. Sword clashes ring out. Bursts of flame and wind stir the street. The sound of gushing water surrounds them. And suddenly, everything stops. On one end of the street, stands the demon
Rengoku, blood dripping and cuts healing. In front of Tanjiro stands Giyu and Sanemi,
the Water and Wind hashiras, breathing hard. And these two would not just show up randomly. I think it is entirely possible that they
would have been hunting Rengoku this whole time, and have just now caught up to the former
hashira. So Giyu looks back at the boys and would probably
order them to flee. But Sanemi cares less about them, and stares
down at the burnt corpse of Tengen and his rage boils over. He shouts at Rengoku, cursing him. Now that they’ve tracked him down, they
are going to end him. Rengoku smirks, flames rising around him,
and the battle resumes. Zenitsu would probably ask if they should
flee, but Tanjiro and Inosuke would not even respond as they strain to keep up with the
incredible display of power in front of them. And we know from later in the story, that
the Upper Moon one, two, and three demons are pretty far above the power levels of the
individual Hashira. And while Rengoku hasn’t quite reached that
level yet, he is certainly much stronger than anything that the Hashiras have faced before. So this definitely isn’t going to be an
easy battle. However, Giyu and Sanemi are two of the strongest
Hashira and together they manage to keep Rengoku occupied. The sun is coming soon, so they must stay
alive until it arrives. As the battle continues, the town burns. Screams fill the air. And the Hashira are distracted by trying to
keep the innocent people alive. Meanwhile, Rengoku delights in the chaos,
causing more destruction with his flames. Amidst the burning town, Tanjiro finds himself
torn. He knows that he is outmatched in a battle
of this level, but he cannot just stand by and watch his friend’s perish. And despite it all, he refuses to give up
hope that Rengoku can still be saved. But time is ticking away. In the blink of an eye, Giyu is engulfed in
flames, and Sanemi’s attempt to save him earns him a wicked slash across his leg. The two Hashira stumble, and Rengoku charges
towards them. The battle begins again, but the Hashira are
clearly losing their grip. And I think it’s at this point that Tanjiro
would not be able to hold himself back. As always, when he is most desperate, Tanjiro
finds the next level of strength. Tanjiro’s heart races as he feels the rhythmic
power of sun-breathing filling his body. Giyu cuts Rengoku across the chest, but flames
explode from the wound, stunning the water hashira. Rengoku grabs Giyu by the throat and squeezes
tightly. Giyu gasps, his neck bulging, but suddenly
Giyu is free and Rengoku’s severed hand falls to the ground. Tanjiro stands over a breathless Giyu. His demon mark flares on his forehead, giving
him the strength to fight. As always, when Tanjiro is most desperate
he finds the next level of strength. Rengoku grins, blocking a blow from Sanemi
and then coming after Tanjiro. But Tanjiro is furious. The rage fuels his muscles and he leaps forward
so quickly Rengoku can barely block the strike. Together, the three demon slayers rain blows
on their former friend. With each strike, Tanjiro shouts memories
at Rengoku. Reminding him of their treasured time together. How he laughed with them. How he trained them. How he was willing to give up his life for
them. The memories fuel Tanjiro’s spirit, but
nothing seems to break through to Rengoku. But Tanjiro keeps trying because this demon
was his friend and I don’t think he would ever give up on him. But Tanjiro is slowing. Exhausted, he slips, and gets tossed to the
side. Giyu and Sanemi are quickly downed as well. They simply cannot keep up with the stamina
and recovery of this overpowered demon. So Rengoku stands over them, ready to deliver
the final blow. But Tanjiro rises again. His sword is gone. His breaths are heavy. His sun-breathing flares. And he stares the demon in the eye. And he does the only thing that he can. Tanjiro yells Rengoku’s name. Over and over again, he repeats it. Trying to reach down and awaken the buried
memories. Because just like his sister, Nezuko, Tanjiro
has to believe that the human is still inside of this terrifying demon. And with each word, Rengoku eyes grow unfocused. The flaming sword lowers. And suddenly tears form in the dark pits of
his eyes. And a word forms on his lips. “Tanjiro.” The flames falter. Sanemi goes for another strike, but Rengoku
blocks it. “Sanemi.” His gaze turns to Giyu and he calls the Water
Hashira’s name as well. And then Rengoku, the former flame Hashira,
drops his sword. He stares at his hands, tears running down
his face, as he looks at the Demon Slayers in front of him. Tanjiro has reached him. His memories return. But so do the shame and guilt that he has
buried all this time. And with Rengoku finally coming back, there
are a few ways that this could go. If he is truly returned, the demon slayers
could bring him back with them. However, as we saw with Sanemi when he first
met Nezuko, when a demon kills a human, some Hashira believe there is forgiving that sin. So while emotions overwhelm Rengoku, Sanemi
goes for a death strike, but Tanjiro steps in front. He kneels before Rengoku and tells him that
he can still choose to come back. He can still choose to do good, but Rengoku
doesn’t believe him. His eyes turn to Tengen’s burnt body, and
his cries grow even louder. And he simply asks Sanemi to end him. And the wind hashira is more than willing,
until a haunting laugh echoes down the dark street. Muzan has arrived. Because while Muzan was initially disappointed
he couldn’t get information about the Demon Slayers when they first met, he probably knew
that at some point Rengoku would regain those memories. So he was just waiting all this time. And With Rengoku’s memories returned, Muzan
reads Rengoku’s mind, and finally learns the secrets of the Demon Slayer Corps, including
where to find their base. The demon slayers rise. Tired and ragged, they face down the demon
king. Muzan applauds Rengoku for being so useful,
and then he calls the former Hashira to his side. He tells Rengoku that he can use that guilt
and shame to grow stronger. But Rengoku doesn’t listen. Instead he rises. He begs everyone to flee, reminding them that
the sun is rising, and Muzan can’t stay here long. Muzan scowls, and tries to trigger the curse
that will instantly kill Rengoku. But it doesn’t work. With his memories fully returned, and his
humanity with it, Rengoku’s connection to Muzan has been severed. Now we know that Muzan is insanely powerful. Way more powerful than even the Upper Moon
demons, so it is possible that he kills all of them right here. But to continue the story, let’s assume
that with the sun close to rising, Rengoku stands to face the demon king. He tells the others to run. And without hesitation, Giyu and Sanemi take
the others and flee. And let’s assume that Rengoku can hold him
off for at least a short while before Muzan eventually ends the former flame hashira’s
life. And with the sun rising, the Demon Slayers
manage to retreat safely to the Demon Slayer Corps base. Despite the heart-wrenching tragedy of losing
Tengen and Rengoku for a second time, there is no time to rest. With Muzan now aware of their location, it
would only be a matter of time before the demons launch an all out assault on the Demon
Slayer Crops. And this insane, all-out battle will require
Tanjiro and the other Demon Slayers to summon every ounce of strength, skill, and courage
they possess just to survive. But one thing we do know is that Tanjiro will
never give up protecting his friends, so he would certainly unlock his full potential
to defeat the demon king or die trying. And if you want to watch my full breakdown
of why this part of his character makes Tanjiro a fantastic great protagonist, you can click
right here. Thanks for watching.
