The experiments began immediately.
Demon blood behaved unlike anything I'd ever studied—magical or otherwise. Even preserved, it wasn't inert. It responded. Shifted. Adapted.
Alive in a way that bordered on will.
I began cautiously.
Drops of blood were isolated in enchanted glass, subjected to controlled exposures of magic. Fire spells first—pure, refined flame. The reaction was muted. The blood darkened slightly, thickened, but did not combust.
Interesting.
Lightning charms produced spasms, momentary agitation, but no lasting damage. Ice magic slowed activity but didn't truly halt it. Even prolonged exposure to corrosive spells resulted in only partial degradation before regeneration attempted to resume.
Demon flesh behaved similarly.
Muscle fibers resisted transfiguration more than expected. The magic took, but imperfectly—as if the body rejected foreign alteration on a conceptual level. Almost like an internal system continuously correcting deviations.
A self-repair curse embedded into every cell.
But not all magic was equal.
Soul-adjacent magic—necromancy, blood magic, and ritual-based enchantments—produced noticeably stronger reactions. The blood recognized it. Responded more aggressively. As though it was closer to the source.
That narrowed things considerably.
I focused on the blood.
Under magnification—both mundane and magical—I observed structures that shouldn't exist. Patterns within patterns. Something akin to a spell matrix woven directly into the fluid itself.
Not cast.
Grown.
Muzan hadn't merely cursed people.
He had rewritten them.
I tested replication next.
Using alchemical reconstruction, I attempted to synthesize demon blood from its components—iron content, abnormal proteins, enchanted residues. The result was close.
But lifeless.
No regeneration. No activity. No hunger.
A failure.
So I adjusted the approach.
Instead of recreating demon blood exactly, I tried isolating its principles.
Longevity.Regeneration.Cellular obedience.
And then I found it.
The most disturbing—and promising—result of all.
Demon blood did not generate immortality on its own.
It acted as a carrier.
A vector for something deeper.
A binding curse, keyed directly to Muzan Kibutsuji's existence.
The moment demon blood entered a host, it didn't just enhance the body—it established a connection. A thread. A channel.
That was how he controlled them.
That was how he read their thoughts.
That was how he erased them.
The blood wasn't the chain.
It was the leash.
I leaned back slowly, fingers steepled, eyes dark with understanding.
"So that's how you do it," I murmured.
If I drank demon blood as-is, I wouldn't become immortal.
I'd become owned.
But the implications were staggering.
If the curse could be identified…If the binding could be removed…If the regenerative properties could be preserved without the connection…
Then demonhood without submission was possible.
True immortality.
Independent immortality.
My lips curved faintly.
Tom Riddle had split his soul because he didn't understand biology well enough.
Muzan had mastered biology but shackled it to tyranny.
I would do neither.
I began writing new notes—pages filling rapidly with runes, formulas, hypotheses.
This wasn't reckless experimentation.
This was the beginning of a new species.
And if Muzan ever discovered what I was doing…
He wouldn't send demons.
He would come himself.