Demon Slayer has kept fans at the edge of their seats throughout the first season and the Demon Slayer: Mugen Train movie, with its lovable characters, a riveting plot, and spectacular visuals.
The Breathing Techniques of the Demon Slayer Corps and the Blood Demon Art of higher-level demons in the series, especially, are popular concepts due to their importance in the story and their stunning execution.
So, with Season 2 in full throttle and Nezuko gearing up for battle with her brother, let us understand precisely how the Blood Demon Art works.
Disclaimer: It may contain SPOILERS for the Demon Slayer anime and manga!
How Blood Demon Art works
To understand how the Blood Demon Art in Demon Slayer works, we must first understand demons themselves. Like Western vampires, these monsters in the anime require humans as a primary source of sustenance, disintegrating into ashes when exposed to sunlight.
They also have incredible regeneration and healing abilities, making them extremely hard to kill without using Nichirin swords to chop off their heads.
One of the facts we find out early in the series is that all demons are directly linked to their progenitor, Kibutsuji Muzan. Only Muzan can turn humans into demons, as he did with Tanjiro's sister, Nezuko, after massacring their entire family.
Blood Demon Art is an ability possessed only by high-level demons, i.e., demons who have eaten a lot of humans. This skillset in the Demon Slayer series is unique to every demon who possesses it and almost always requires the demon's own blood to activate their ability (or abilities).
Abilities acquired by a demon include heightened combat abilities, producing poisons in their body, hypnotism, and mind control, among many other unique abilities.
These skills, however, require fine-tuning for them to become assets, as we learn from Yushiro, who calls his Blood Demon Art incomplete.
Blood Demon Art users in Demon Slayer
Some of the most significant demons practicing Blood Demon Art in Demon Slayer include the Twelve Kizuki, under the direct command of the Demon King Kibutsuji Muzan, Nezuko, Tamayo, Yushiro, and Muzan himself.
Tamayo and Nezuko are the only two demons in the series who have managed to sever the connection between Muzan and themselves, thus freeing themselves from his control. Tamayo's Blood Demon Art constitutes of using her blood as a truth serum or its fragrance as a hallucinogen.
Nezuko can heat up and explode her blood at will and combine her blood with Tanjiro's Nichirin sword to inflict more lethal combination attacks against more powerful antagonists, which we see in episode 19 of Demon Slayer Season 1.
Interestingly, being a doctor, Tamayo modified her physiology to require as little human blood as possible for sustenance. At the same time, Nezuko is shown to not require human consumption at all, relying on sleep instead. She is the only demon in the Demon Slayer series who has been able to unlock Blood Demon Art without feeding on humans at all.
Muzan's Blood Demon Art is, of course, befitting his status as the predecessor of all demons. Besides human transformation into monsters, he can also use his blood to either enhance the strengths of demons under his command or destroy them.
Muzan is also able to shapeshift freely and has been alive for hundreds of years.
He has, however, been unable to overcome a quintessential weakness of all demons: immunity to sunlight. It is his obsession with creating the perfect demon that fuels him to get hold of Tanjiro and Nezuko at any cost due to their lineage as Sun-worshippers and his belief that the latter could be his answer to achieving true immortality.
Blood Demon Art in Demon Slayer can take on many forms, ranging from demons manipulating their blood as spider-silk to using drums to flip rooms to integrating themselves into non-living objects.