Without a doubt, this non-human entity was likely the god spoken of by the Beast-Eared Girls.
The nearly ten thousand experimental logs culminated in the phrase "I have failed." But this wasn't the end; afterward, they transitioned into a diary format, with the Chief Scientist apparently recording her daily experiences.
Who keeps a diary these days? But Lingsha could roughly guess why the Chief Scientist kept this journal.
Her civilization had been nearly destroyed, but whether a civilization truly perishes depends on whether it leaves anything behind. If even a single artifact from that civilization survives to be discovered in the future, it can't be considered completely extinct.
The first diary entry detailed the technological strengths of her world's civilization, along with major historical events. For instance, there had only been one world war, and nuclear energy had never been developed.
The second entry described once-thriving cities, listing their names, locations, unique features, and other details.
The third diary entry shifted to descriptions of foods the writer had once enjoyed but could no longer obtain.
It was clear that these descriptions were entirely disorganized, more like a stream of consciousness. Reading between the lines, Lingsha could almost visualize the last person on this world, sitting alone before the computer, head bowed as they silently typed away at the keyboard.
However, the tenth entry marked a distinct shift:
[The Heavenly Flaw has undergone an unknown change. Unfamiliar monsters have appeared near the laboratory, but I easily killed them.]
[According to the First Laboratory's research, I have conquered Death. A new disaster will inevitably follow—could these strange creatures be it?]
[Wait! If the First Laboratory's conclusions are correct, then the Heavenly Flaw itself is a colossal disease. It will continue to spread, infecting other parallel worlds. Does that mean I might find a way to travel to those worlds? Surely there must still be humans in those worlds?]
In just ten days, the Chief Scientist regained her motivation and resumed her research into parallel worlds.
Her subsequent diary entries revealed that she frequently ventured out to eliminate monsters. During one such expedition, she stumbled upon several stray dogs clinging to life. Overwhelmed by loneliness, she immediately took them in.
Death only affected humans, leaving animals unharmed. However, dogs, being so closely intertwined with humanity, had suffered a drastic population decline after the extinction, though they hadn't been completely wiped out.
With pets for companionship and a clear purpose, the monsters emerging from the Heavenly Flaw posed no threat to her. While her diary lacked detailed accounts of her combat abilities, every enemy she mentioned died instantly upon encountering her, suggesting her strength was extraordinary.
Everything seemed to be progressing favorably, but... as time passed—a year, a decade, a century—the Chief Scientist made little progress in her research on parallel worlds.
After all, her expertise lay in biology, not the enigmatic realm of parallel worlds. It was like tackling advanced calculus: without the innate aptitude, no amount of effort could unlock the solution.
The pent-up emotions of the past century finally erupted when the first stray dog she adopted died.
Yes, this Chief Scientist had survived for a hundred years after humanity's demise, and her dog had lived just as long. As a master of biological manipulation, extending her beloved companion's life had been a trivial matter.
Yet, even as the dog's body remained perpetually youthful, its spirit grew increasingly weary. It was like an ordinary person, destined for a century, forced to endure a thousand years of identical, monotonous days.
Dogs, by nature, were meant to live only so long. Forcibly extending their lives beyond this limit was ultimately a form of torture. In the end, the dog lay cradled in its master's arms, its breath growing shallow until it slipped away.
Though its heart still beat and its lungs still drew air, it would never awaken again.
In one of her final journal entries, the Chief Scientist wrote:
[I'm so tired... I don't want to continue this research anymore.]
She had lost all hope, unsure how much longer she could endure and whether her efforts would ultimately succeed.
Scrolling to the end, Lingsha discovered the diary entry was a video. For the first time, she saw the Chief Scientist: a strikingly young woman with long, dark hair.
Yet her face was etched with exhaustion. Despite her youthful appearance, her spirit seemed withered, like that of an ancient elder nearing death.
Nearly a hundred dogs of various breeds surrounded her: Golden Retrievers, Huskies, Czech Wolfdogs, and countless others.
Speaking wearily into the camera, she said:
[Over the past century, my research hasn't been entirely fruitless. I've learned that if my world is completely destroyed and declared "dead," it will transform into a "source of infection," spreading the Heavenly Flaw to other worlds.]
Having personally witnessed the destruction of her own world, she naturally didn't want other worlds to suffer the same fate. But she was too tired. Gazing at the first dog she had lost, now dead in her arms, she longed for the sweet release of an eternal, dreamless sleep.
Finally, she turned to the pack of dogs beside her and said, "The future of this world rests on your shoulders. Devour me, share my power, and after I die, slaughter every monster that enters this world."
The Chief Scientist had developed her final invention: an extraordinarily potent injection. She administered it to herself.
She committed suicide, but in doing so, she transformed her corpse into an infinitely regenerative resource with immense power. Her death in this place was the reason the land became a fertile grassland.
Deliberately emitting an irresistible scent, her corpse drove the dogs into an uncontrollable frenzy. They devoured her flesh, rapidly undergoing biological evolution. Within mere generations, they transformed into the Beast-Eared Girls of today.
As their intelligence grew with each evolutionary leap, the Beast-Eared Girls gradually resisted their instinctive urge to devour. Humanity's once most loyal companions began to follow the commands etched into their very genes:
Hunt down monsters! Protect their former masters!
Through the Chief Scientist's sacrifice, this world, once on the brink of destruction, had become a bulwark against dimensional rifts, a 'wall' protecting other parallel worlds.
P.S. Since Beast-Eared Girls are essentially humans evolved from dogs, their fundamental nature remains canine, making them immune to Death.