The four step drug used to kill [SPOILER]Explained, explained

Summary

• The anti-Kibutsuji drug was crucial to defeating Muzan by transforming him into a human being, quickly aging him and breaking him down at the cellular level.

• The drug weakened Muzan substantially, prevented his escape from the battle and stopped his regenerative abilities.

• Without Tamayo's victim to inject the drug and Shinobus expertise, Muzan would have easily won the last battle.

During the last battle over Demon Slayer: Kimetsu No YaibaThe Demonsklayer Corps is facing the most powerful demon of all time, Muzan Kibutsuji. Many lives had already been lost to this monster, as even the strongest Hashira could not counteract his overwhelming power.

When Muzan continued to kill the members of Korps, he could not realize that there was another powerful weapon that had been prepared specifically to defeat him. This weapon was none other than the Anti-Kibutsuji drug. Made from the collaborative efforts from Tamayo, Yushiro and Shinobu, this drug showed to be extremely useful to defeat Muzan once and for all.

Four -effect drug preparation for the battle against Muzan

How did the anti-Kibutsuji drug work?

Despite Shinobus deep hatred of demons, she puts her nails and worked with Tamayo, and knew it was the only way to stop Muzan. Tamayo felt Muzan very well and was aware of his strengths and weaknesses.

We do not have the strength to fight Muzan forward, so we remove his power instead – Tomayo

Her knowledge, combined with Shinobus's expertise within Wisteria Poison used against demons, gave us the powerful anti Kibutsuji drug that turned the odds for the battle to their advantage. The drug itself was supposed to have four major effects on Muzan.

Convert Muzan to a human

The first effect of the drug was to convert Muzan into a human being. This was definitely quite risky because the transformation into a demon is considered permanent and the only way out of this curse is death. However, Tamayo had spent ages finding a possible cure to turn the curse and turning a demon into a human again.

Tamayo had also studied Nezuko's blood after every battle she went through. However, the first effect failed, and if only it had worked, Muzan would have turned into a human being and it would have been much easier to defeat him. The drug weakened him considerably, but Tamayo and Shinobu knew they would need much more than this to defeat Muzan. To ensure his downfall, they designed it with another three effects.

Fast aging

The second effect of the drug was to counteract the regenerative speed of Muzan. He was so powerful that he could recover from the deadliest strikes directly and even though he was shredded in the small pieces, he would regenerate within seconds.

The drug accelerated Muzan's aging, which caused him to age about 50 years per minute, which would drastically weaken his body over time. This made him very vulnerable, and after about 5 hours of the drug consumed, Muzan began to age quickly. He began to lose his strength and endurance and his attacks became much weaker.

Prevents Muzan from escaping from the battle

Tamayo knew that when Muzan reached the border with defeat, he would divide into smaller parts to flee from the battlefield and regenerate himself after he reached a safe place.

I don't have to be stronger than you to kill you. I will only make you weaker. Just as you will do what it takes to keep me alive, I, no, we will do what it takes to kill you – Tamayo to Muzan

So the third effect was to prevent Muzan from dividing up and escape so that Korps could end him once and for all.

Break Muzan at cellular level

The last and most deadly effect of the anti-kibutsuji drug was to kill Muzan by breaking down the body at the cellular level. This effect turned out to be the ultimate key in defeating Muzan as his cells continued to die over time, which also stopped his regenerating and healing abilities.

When the drug completely took over Muzan's body, the demon king fell. While trying to stay alive by eating the members of Korps, none of it played because the drug had already done his job.

The role of the drug in defeating Muzan

This drug was one of the most important reasons why Demon Slayers could defeat Muzan for good. Without this, Muzan would have continued to fight on his full potential and would have killed every single member of Corps I Demonsklayer.

If it wasn't for Tamayo's victim to inject the drug into Muzan and Shinobus help to make it strong enough to defeat him, Demon King would have won easily.