Demon Slayer: The Blue Spider Lily's Deception

Kiriya looked at the tea in his cup, took a moment to gather his thoughts, then began explaining to Yushiro.

“During the Heian era, a kind doctor used his medical skills to prolong Muzan's life, even though other doctors had declared that Muzan wouldn't live past the age of twenty.”

“But as his illness continued to worsen, Muzan cruelly murdered the good doctor treating him.”

“Not long after the doctor died, the medicine began to take effect, and Muzan became a demon.”

“Muzan looked through the doctor's prescriptions and learned that one ingredient was missing: the Blue Spider Lily. Finding it would cure him.”

“Now, here's the question.”

“A kind doctor uses an experimental medicine to treat a patient with a universally recognized incurable disease. The patient's life is prolonged, but his condition keeps worsening. And the doctor, without knowing in advance that Muzan would kill him...”

“How could he have written that a nonexistent medicine was missing in order to strengthen the drug?”

Yushiro analyzed the matter calmly.

A kind person would only try to invent a nonexistent medicine to save himself if his life were in danger.

But that doctor was killed by Muzan on the spur of the moment.

In other words, the Blue Spider Lily existed.

“Or perhaps the good doctor already knew from the start that Muzan would become a man-eating demon if he didn't absorb the Blue Spider Lily.”

“Put another way, if the good doctor who treated Muzan already knew how to use medicine to turn someone into an immortal demon who survived by eating people, why wasn't he the first to benefit from it?”

(With so many Demon Slayer stories out there, has no one thought of writing a sequel?)