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Can a demon use a Nichirin sword?

A Nichirin sword is a special sword in the demon slayer universe that is used to kill demons. It is forged from a unique ore that reacts to sunlight, turning bright red when exposed. The red blade is said to destroy a demon’s body and prevent regeneration. So an important question is – can a demon actually wield a Nichirin blade themselves? Let’s analyze this in detail.

Properties of a Nichirin Sword

A Nichirin sword has the following special properties:

  • It is forged from a rare ore found on Mount Fujikasane
  • The ore absorbs sunlight andreflections, giving the blade a distinct reddish color
  • It becomes harder and more durable when exposed to sunlight
  • It prevents demons from regenerating their flesh when cut
  • It purified the demon’s blood when cut, leaving no traces behind

These properties make the Nichirin blade extremely effective against demons. The prevention of regeneration ensures a fatal blow. The purification prevents the demon’s blood from infecting humans. Together, this makes it the perfect anti-demon weapon.

Effects on Demons

When a demon is cut by a Nichirin blade, the following effects occur:

  • The wound burns due to the purification properties
  • The demon’s flesh turns to dust around the cut
  • The demon is unable to regenerate their body around the wound
  • If decapitated, the demon dies permanently
  • The purified blood leaves no traces behind

Essentially, a Nichirin blade delivers fatal damage to a demon’s body. Once cut, the purification stops their trademark regeneration abilities. Over time, this leads to the demon’s permanent destruction.

Demon Biology

To understand why demons are vulnerable to Nichirin swords, we must analyze their biology:

  • Their cells contain high concentrations of Muzan’s blood
  • Muzan’s blood grants them regenerative abilities
  • Their flesh and bones are infused with this blood
  • It is this blood that allows them to regenerate entire lost limbs or organs
  • Removing their head eliminates all traces of this blood

A Nichirin blade purifies the demon’s blood on contact. This stops the spread of Muzan’s cells near the wound, preventing regeneration. So a Nichirin weapon is specifically designed to counter a demon’s natural abilities.

Why Demons Cannot Wield It

Now we get to the crux of the matter – why can’t demons use Nichirin swords themselves? There are a few key reasons:

  • The purification weakens demons significantly
  • Prolonged contact with the sword causes burning pain
  • A single cut could permanently maim a demon’s body
  • Decapitation by their own Nichirin blade would be fatal
  • Demons rely heavily on regeneration in combat

Wielding a Nichirin sword against other demons would be extremely risky. The blade does not distinguish friend from foe when purifying blood. Any accidental cut could cause fatal or crippling damage. The weakening effects also put the demon swordsman at a disadvantage. Overall, the risks far outweigh any potential benefits.

Some key drawbacks of a demon using Nichirin swords:

Drawback Description
Weakening Purification effects drain demonic power
Pain Prolonged contact burns flesh
Self-harm Risk of accidental permanent damage
Decapitation Single cut could kill wielder


There are two exceptions where demons can technically withstand contact with Nichirin blades:

  • Muzan Kibutsuji – As the progenitor demon, he lacks typical weaknesses
  • Kokushibo – Gained immunity after consuming many demons

However, even these powerful demons avoid Nichirin blades due to the risk and pain involved. They may survive accidental cuts but still find the contact unpleasant. For all other demons, attempting to wield a Nichirin sword would be suicidal.


In conclusion, typical demons cannot safely wield Nichirin swords themselves:

  • Their biology is vulnerable to the purifying effects
  • Contact causes severe pain and weakening
  • Self-inflicted cuts could lead to permanent maiming or death
  • Only the most powerful demons can withstand it briefly
  • The risks outweigh any potential benefits in combat

So while the Nichirin blade is the perfect anti-demon weapon, it is not one that demons themselves can use. The unique properties that make it so effective against them, also prevent them from wielding it against their own kind. In the hands of a skilled demon slayer however, it is an invaluable tool to permanently destroy demons.


  • Kimetsu no Yaiba (Demon Slayer: Kimetsu no Yaiba) anime and manga
  • Ufotable anime adaptation
  • Koyoharu Gotōge manga chapters
  • Kimetsu no Yaiba Wiki – Nichirin swords, demons
  • Reddit threads on Nichirin sword lore