He is mad.
That man is utterly insane.
Even as he dies from my poison, he forced himself to tear out my heart and swallow it whole.
Which of us is the human, and which is the demon?
I came here on a mere whim.
Having never turned a user of the Breathing Styles into a demon before, I was simply curious to see the reaction.
If he became a demon, well and good.
A demon created from a human who masters the breath would surely be powerful—perhaps powerful enough to overcome the sun itself.
Especially one who stands at the pinnacle of that organization.
If it were this man, who gave the Demon Slayer Corps the very swords used to hunt us and systematically slaughtered the demons I painstakingly created, it might have been possible.
But he refuses to become a demon?
Then he must be erased.
Surely, no other human exists who surpasses him.
He obtained everything the Corps possesses one step ahead of the rest and bestowed it upon them.
Even among the Pillars, not a single one surpasses him.
However, that is only by the standards of a human.
Fragile humans, whose prime ends the moment they lose a limb or suffer a fatal wound, can never defeat a demon.
The difference in our biological status is that vast.
Even if he stands at the zenith of those who hunt demons as a human, he is still just a human.
He cannot hunt me, the pinnacle of all demons.
That is the logic of this world.
And yet.
Why does he refuse to die...?
For five hundred years, anyone I grazed even once was reduced to scraps of meat. How are you still holding on?
For five hundred years, no one could match my speed. How are you keeping pace?
For five hundred years, no one could withstand my lethal poison. How are you still standing?
For five hundred years, I had forgotten the meaning of pain. How are you forcing me to remember it?
In five hundred years of life, no one ever thought of—much less executed—the idea of tearing out my heart to eat it. Just what is this madman?
Who... what are you?
From the Breathing that sees through everything to the demon-like Mark, and even that Crimson Blade that burns my very flesh.
Must one be this insane to manifest all of that?
Or were you mad from the start, and that is why you could create it all and stand at the top?!
Questions flood my mind as a certain emotion begins to erode my thoughts.
Even if I judge that he is no threat to my life, even if I keep suppressing the thought...
That sensation I had forgotten during five hundred years of life, though it may take a different form now.
Fear is filling me.
Faint, yet crawling upward—the emotion called fear.
That madness... tearing out my heart and chewing on it, swallowing every single morsel of the pulsing organ without leaving a scrap behind.
I am feeling this emotion because of the sheer lunacy he is displaying.
But no matter.
What he has done is a blunder.
Even if eating my heart was an unexpected variable, it is a mistake that will only push him further into the abyss.
Whether he turns into a demon or not, my blood is a lethal poison that collapses cells. If he becomes a demon, he falls into my grasp whether he likes it or not.
If he continues to attack after becoming a demon, I need only make his cells go berserk and kill him.
If he fails to become a demon, he dies as he is.
Chewing and swallowing my heart is the same as injecting a massive amount of my blood directly into his system.
Look.
"Cough!"
He is vomiting blood.
Having finished my heart, the man is now spewing blood from every orifice, standing motionless.
Though it bothers me that his blade remains crimson...
I will not wait for him to succumb to the poison.
I do not know what else this madman might pull next.
"With this."