Why Couldn’t Asa/Yoru Turn Denji Into A Weapon (Spinal Cord Sword)?

Chainsaw Man chapter 117’s ending gave us one of the biggest cliffhangers of the series. After dealing with the Eternity devil at the aquarium, Asa and Denji shared a moment, as the latter asked her out on a date.

Thanks to Denji’s actions, Asa seemingly developed feelings for him. But a romantic development was not in place for those two. Instead, Yoru jumped the gun and decided to set their plan of turning him into a weapon into motion.

Enter, Denji spinal cord sword!

Asa/Yoru turn Denji into a weapon, the spinal cord sword

Yoru’s action definitely made the fandom sweat, but not for long. Chainsaw Man manga wouldn’t be the same without Denji right? So there should be no possibility of Denji turning into a weapon right?

Well, for starters, Asa has seemingly usurped Denji’s role as the protagonist of the series in part 2. To add to that, the teaser poster which was revealed for CSM part 2 features Asa holding a chainsaw. 

Fujimoto being a madlad, it wasn’t out of the realm of possibility to fear the worst happening, i.e. Denji turning into a weapon at Asa/Yoru’s hands.

However, that did not come to pass. Huge sigh of relief? 

But then again, was this just because Denji is an integral part of the manga. Partly yes, but there are also other in-universe reasons which prevented him from being turned into a weapon by Asa/Yoru.

Allow me to break it down for you!

Understanding War Devil’s powers:

Before we get to the exact reason, we need to understand some technicalities of War Devil’s powers and also the whole situation between Asa and Denji.

According to what Yoru said in chapter 99, the War Devil has the power to turn something that belongs to them into a weapon. And then she proceeds to hypothesize that if a person were to fall for her, it would technically mean that they belong to her and she can turn them into a weapon.

Related: Is Asa a fiend or a hybrid in Chainsaw Man?

Yoru explains the War Devil's powers in Chainsaw Man chapter 99

Now, coming to the situation between Denji and Asa, we notice that Asa is the one who falls for Denji, and not the other way around. It’s not like he didn’t like her. Denji most probably just saw her as a potential girlfriend, and hence his request for a second date.

Think about it, the aquarium date did not go as planned. He was left bored and disappointed by Asa’s behavior. On top of that, she reminded him a lot of Power, and even Makima to a certain extent. There is trauma associated with both of them in Denji’s mind.

True, he did ask her out on a second date, but that was mostly because of the fun time they had towards the end at the aquarium. The date was more like a second chance, for him to get to know her better, or to just jump to sex!

Going by that logic, Asa was the only one with romantic feelings for Denji at that particular moment. And Yoru being someone who has not experienced love before, misjudged the entire situation and acted prematurely.

Romance angle aside, there is also the case of what Asa thinks truly belongs to her.

When she turned the Aquarium into a weapon, she envisioned buying it by offering up a million yen. While the money she offered might have been less, it was how she interpreted the whole situation that mattered the most. A sort of twisted superiority complex was at play, if you may say so.

In Denji’s case, I am pretty sure Asa plainly just fell for him. There was no wicked controlling mindset or superiority complex involved there. And even if Denji did develop feelings for Asa at that moment, it wouldn’t matter because she would not be aware of it.

In short, there was no way Asa felt she completely owned Denji then. She impulsively liked him, regardless of the plan she cooked up with Yoru. And there was no saying if he reciprocated her feelings for him.

This is one of the reasons why Asa could not turn Denji into a weapon. And this is also the conclusion that Yoru comes to when she fails spectacularly!

However, there’s also the possibility of Yoru’s hypothesis being wrong. Considering what we have seen so far, both Asa and Yoru are unreliable narrators. Taking their words for fact wouldn’t be a wise choice.

Just because someone falls for you doesn’t mean they belong to you. That’s just Yoru’s interpretation of it. 

I mean, the devil herself accepted that she is unfamiliar with human society in the same chapter (99), so we can’t completely rule out the scenario where her assumption falls flat on its face, like Asa.

Yoru is not familiar with human society Chainsaw Man chapter 99

Denji belongs to someone else:

Let’s continue the discourse of whether Denji actually belonged to Asa. The reason why she couldn’t turn him into a weapon could also be because he, in fact, belonged to someone else.

While we didn’t know this when Yoru was trying to turn him into a weapon, the answer was pretty much clear come chapter 119, when we finally get to see Nayuta.

Not only did she brand Yoru a thief for trying to make out with Denji, in the very next chapter, she also claimed that Denji is her property.

Nayuta calls Denji her property
Nayuta’s way of saying Yoru kissed Denji

Though he vehemently denies it, their interactions throughout the chapter convince me that Nayuta has the upper hand in their dynamic.

We know Denji cares deeply for Nayuta, and he might be willingly let the latter have her way, however, the bond between them was much closer compared to that of Denji and Asa’s. 

This sounds superficial, I know, but considering the fact that Nayuta is the control devil, it is possible that she saw Denji as her personal property. And this counted, at least in the Chainsaw Man universe, as Denji belonging to her and not to anyone else.

If we were to equate Nayuta to Makima, we know that rhyme and reason don’t work when it comes to her powers. It’s a whole different ball-game.

Related: Makima’s powers and abilities explained!

This only adds more credibility to the assumption that Denji actually belonged to Nayuta and that’s the reason why Asa/Yoru couldn’t turn him into a weapon.

Denji is a hybrid and stronger than Asa:

While I have gone on and on about relationships and bonds, there are some other reasons for Asa’s failure that I would like to present.

Yoru has stated multiple times in the past that in her current stage she is no match for Chainsaw Man, at least not without a very powerful weapon.

Yoru admits she can't defeat Chainsaw Man, chapter 112

This meant that Denji was stronger than her when she tried to turn him into a weapon. This could be another reason why Yoru couldn’t turn Denji into a spinal cord sword.

Let’s also not forget that Denji is an immortal hybrid, and he is just built different. This is not the first time a devil has tried to transform Denji and failed.

In Chainsaw Man part 1, the Doll Devil’s powers did not work on Denji and Power, both of them were not transformed into dolls. Even the Zombie devil’s powers, which involved transforming people into zombies, did not work on him.

Denji and Power are immune to Doll Devil's ability, Chainsaw Man chapter 59

This suggests that he is immune to the the physical transformation type ability (A more detailed explanation here). Let’s do some tinfoily assumptions on why it works this way for hybrids and fiends. There are two possible reasons why this could be happening:

  1. Their immortality (or semi-immortality) grants them physical superiority over normal people.
  2. In case of hybrids, their bodies are already bound by a contract to a physical transformation, i.e, turning into the Chainsaw Man, Crossbow Devil etc, which effectively nullifies any other external physical transformation that is brought about by a devil’s powers.Tinfoil? Yes!

Moreover, it could be for a very simple reason that physical transformation abilities are only meant to work on humans or objects.

Let me elaborate on this a bit more. Throughout part 2, Asa is never shown to turn a devil or a hybrid into a weapon. Even the Hand Grenade from chapter 98 and the Yuko Leg Sword from chapter 110 were made out of parts that were cut off from the devil.

Going by these observations, this could be another reason why Asa was not able to turn Denji into a weapon!


I did present multiple reasons for why Asa/Yoru failed. However if you were to ask me, then the Denji being a hybrid and resistant to the War Devil’s powers is why Asa was not able to turn him into a weapon.

The discourse on romance and who Denji belongs to is certainly interesting, however, they are just assumptions and there isn’t any concrete evidence backing up those assumptions.

That’s not the case with the third section. And so, I will side with that one for now.

Why do you think Yoru failed? Let me know your thoughts in the comments below!

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