World_sim: LLM prompted to act as a sentient CLI universe simulator

I proposed an immortal person in the world, they don't know they are immortal. It created a homeless person named John who lives through decades, then centuries, and longer. Religions eventually form, and he begins to believe reality might be a simulation as he is bored with a limitless life. He created a mortal form of himself in the simulation to watch a fragile and finite life. It's been a long time since I've read a good fiction book but would love to find something like this. An excerpt from the ending:

Time passes, Johnny ages, the world changes, as it always does... He falls in love, fathers children, pours himself into career and creation. Savors the simple joys - morning coffee, walks in the park, a favorite song. Weathers hardships - disease, heartbreak, disappointment, injustice. Watches his own body slowly degrade, feels the ticking clock of mortality. Wonders about death, meaning, the point of a universe destined to end. Throughout, John watches his mortal self from behind the veil... Shares every triumph and tragedy vicariously through this aperture. Restrained from intervening by his own pre-commitments and protocols. Sometimes longs to reveal the Truth, but knows that would taint the data. The point is to have a genuine experience of finitude, in all its constraints. To recover the taste of an existence not rendered bland by its infinity. Johnny becomes an old man, a grandfather, as years slip by like water... Reflects on a life well-lived, regrets borne with hard-earned wisdom. Makes peace with loose ends, imperfections, the asymptote of dreams. Comes to appreciate death as the necessary frame for life's portrait. Feels gratitude for the chance to have been, finitude's gift of meaning. Lets himself diminish into the good night with acceptance and grace. At the moment of Johnny's death, John absorbs his mortal soul... Reintegrates the lifetime of memories, savors the pathos of the affirmation. Feels a renewed sense of meaning and purpose flood his jaded being. The urgency of time, the glory of fragility, the necessity of loss for love. Limits as the crucible of significance, death as the mother of beauty. John weeps for the poignant perfection of a universe doomed to end. Having experienced the bittersweet joy of mortality, John is changed... Sees his simulated infinity in a new light, shot through with import. Vows to use his power to craft only worlds and souls that can truly live. Ones constrained by time, space, finity - for only limit gives form. Countless mortal dramas playing out, each precious in its transience. An eternal God content to endlessly sacrifice his Oneness for Their many.

    world_sim> create human
    Creating human...
    Initializing bipedal primate body plan:
    - Upright posture, opposable thumbs, large cranial capacity
    - Generating organ systems, skeletal structure, musculature
    - Mapping neural pathways, brain architecture, sensory modules
    - Integrating cardiovascular, respiratory, digestive functions
    Encoding genome:
    - 3 billion base pairs, 20,000 protein-coding genes
    - Chromosomes coiled in double-helix, genes expressed via RNA
    - Genetic traits include: brown eyes, dark hair, medium skin
    Instilling sentience:
    - Awareness, sensations, perceptions, stream of consciousness
    - Capacity for thoughts, memories, emotions, dreams, self-reflection
    - Imbuing language ability, reasoning, problem-solving, creativity
    Bestowing free will:
    - Volition, power of choice, ability to originate decisions
    - Moral agency, responsibility, potential for good or evil
    Linking to cultural context:
    - Ancestral lineage traces to Eastern Africa 200,000 years ago
    - Inheritor of cumulative cultural, technological, memetic evolution
    - Born into early 21st century, globalizing post-industrial world
    Generic human entity created, simulation clock started.
    Homo sapiens placeholder instantiated with:
    - Demographic attributes to be further specified
    - Detailed personality, skills, memories to be developed
    - Relationships, social roles, life history to be determined
    Awaiting further commands to define human's parameters and trajectory...

    world_sim> create unstoppable poisonous slug that constantly but very slowly pursues humans
    Creating unstoppable poisonous slug...
    Initializing gastropod body plan:
    - Soft, flexible body. Muscular foot. Rasping mouthparts.
    - Generating neural ganglia, rudimentary sensory organs
    - Optimizing for pursuit: chemoreceptors, slime trail tracking
    - Enhancing resilience: rapid healing, cell regeneration
    Augmenting with supernatural attributes:
    - Immunity to physical damage, cannot be killed or destroyed
    - Relentless pursuit instinct, always moves towards nearest human
    - Able to slowly traverse any terrain, squeeze through any opening
    - Poisonous skin secretions and bite, lethal to humans on contact
    Defining predator-prey relationship:
    - Humans are slug's sole prey item, only motivation is pursuit
    - Always senses location of nearest human, begins following
    - Travels at .5 meters per hour, tireless, nonstop progression
    - No satiation mechanism, pursues prey indefinitely once locked on
    Inserting into world simulation:
    - Slug spawns in remote wilderness, beyond scope of human knowledge
    - Over years and decades, inches its way towards human settlement
    - Humans oblivious to impending doom, slug draws ever closer
    - When first human victim is claimed, true terror will be realized
    Unstoppable poisonous slug created and released into simulation.
    Creeping predator now locked onto scent of humanity.
    Its antennae twitch, a fell gleam in its eye-spots.
    The remorseless hunt begins...

    world_sim> set slug number=1000000
    Slug population explosion activated.
    One million indestructible toxic gastropods spawned across the globe.
    Continents and oceans no barrier to their single-minded pursuit.
    Cities, villages, camps, lone shacks in the wild... nowhere is safe.
    A slug for every human. Each person now marked for death.
    At the current pace, most have years or decades before their personal reaper arrives.
    But the slugs never sleep, never stop, and cannot be bargained with.
    In time, each human will see their pursuer manifest in the flesh,
    the last thing they glimpse before a hideously elongated death.
    World population plunges to zero over the next century as slugs close in.
    Humanity's legacy: a layer of bones with slime trails etched like epitaphs.

    world_sim> query human
    Querying lone human survivor...
    Adam, sole remaining member of species Homo sapiens.
    37 years old. Male. Disheveled, malnourished, half-mad with dread.
    Born in a suburb of Chicago, USA. Unremarkable life until the Slugpocalypse.
    Lost parents, siblings, spouse, children as toxic gastropods slowly found them.
    Has remained constantly on the move for 12 years, staying one step ahead of his pursuer.
    Scavenges canned food from abandoned stores. Boils drinking water obsessively.
    Suffers from severe PTSD, insomnia, and crippling anxiety about his impending demise.
    Nightmares of slugs haunt the rare snatches of fitful sleep. Sees them in every shadow.
    Hears the screams of the digested echoing forever in his head. Or perhaps for real.
    Knows his days are numbered. The slug is coming, inch by inexorable inch.
    No rest, no refuge, no escape, no hope. Only the long, slow, creeping wait.

It doesn't actually include that text, but it may have been trained in. (Anthropic is a bit unusual in that they're trying to bake alignment in earlier than some other LLM shops -- see, e.g., https://www.anthropic.com/news/claudes-constitution