Notes

Abyssal Ledger (深淵の台帳 — Shin’en no Daichō)
Classification: Innate Cursed Technique → Transmutative/Reality-Editing (high-tier, potentially special-grade)

Theme: Records, ink, rewriting causality

Core Concept
The user manifests an ethereal ledger (a floating, black leather book and a quill of shadow-ink). By writing an “entry” in the ledger that names a fact about a target (a person, object, event), the ledger imposes a new causal constraint on reality: the written fact becomes true retroactively within a bounded scope. Small edits change memories/conditions; large edits rewrite events. Each edit consumes a resource: the user’s personal time (seconds to years of their subjective life), and accumulates an instability called Paradox Friction. The technique’s extreme potential comes from its ability to alter causal history — effectively retconning reality — but that power is dangerously nonlinear.

How it Works (mechanics)
Entry Format: Subject • Predicate • Timestamp (optional). E.g., Kaito Mizuno • Never learned to use Cursed Energy • 2017-04-12.
Scope: If no timestamp is given, the ledger applies the change to all causal chains visible to the user within line-of-sight and social reach (roughly: people the user has met or observed). Adding precise timestamps increases potency but costs more.
Cost: Every entry consumes subjective lifespan. Small factual edits cost minutes–days. Major rewrites cost months–decades of the user’s life. If the user has no lifespan left, the ledger refuses entry.
Paradox Friction: Each edit adds instability. Above a threshold, edits create side-effects (memory fragmentation, reality glitches, spontaneous manifestations of erased possibilities).
Resistance: Targets with strong Domain barriers, Contracts, or “anchoring” techniques reduce or negate ledger edits. Mental fortitude can make memory edits partially resistant.
Signature Techniques
Footnote (小注 — Shochū)

Minor edit. Alters a single memory or small physical condition (e.g., “Target never saw the scar”). Low time cost; low paradox.

Redaction (抹消 — Masshō)

Erase an event or a short period from a target’s timeline (e.g., the last 3 minutes of a fight). Medium cost, medium paradox: nearby people may feel deja vu.

Addendum (追記事項 — Tsuikikō)

Inserts a new, minor fact into reality (e.g., a hidden lock suddenly exists on a door). Costs depend on how entangled the new fact is with existing causality.

Chapter Rewrite (章改変 — Shō Kaihen)

Large-scale rewrite: change the outcome of an important historical event (e.g., “The Siege of X never happened”). Very high cost (years), enormous paradox risk. Usually only usable sparingly.

Marginalia — Contract Binding (余白の契約 — Yohaku no Keiyaku)

The user writes a contract into the ledger bound to another’s name. If accepted (signature, verbal acknowledgement), the contract becomes metaphysically enforceable. Useful for creation of pacts or sealing abilities.

Domain Expansion — Oblivion Library (忘却図書館 — Bōkyaku Toshokan)
Within the Domain, the ledger becomes omnipotent relative to local causality: entries are immediate and require only symbolic cost (writing still consumes time, but subjective cost is scaled down). The Domain’s pages show branching timelines; the user can “select” which branch should be dominant. However:

Using the ledger inside the Domain multiplies Paradox Friction generation.
Opponents can lock pages with their own curses (page-anchors) to defend certain facts.
The Domain is visually a cathedral of shelves and floating tomes; the air smells like old ink and rain.
Visuals & Sensory Cues
The ledger appears as black leather with ink that looks bottomless. Writing leaves faint, bleeding shadows on the world (a ripple).
Every edit causes a soft audible folio-click and a brief coldness like winter breath.
Severe edits briefly show ghostly alternate scenes as overlays before collapsing into the new reality.
Strengths
Reality-level influence: Can change outcomes, erase events, and fabricate bindings.
Tactical flexibility: Memory edits for stealth, addendums for traps, contracts to bind enemies.
Scales with knowledge: The more the user knows about a target’s past, the cheaper and cleaner the edit.
Weaknesses & Counters
Costly: Powerful edits consume large chunks of the user’s life; repeated use can kill the user via accelerated aging or simply running out of subjective time.
Paradox Friction: Accumulation causes glitches: people remember both versions, reality echoes manifest (phantoms from erased timelines), the ledger may refuse entries.
Anchors & Contracts: Pre-existing seals, divine-like Contracts, or true-name magic can block ledger edits.
Precision requirement: Vague entries cause unpredictable side-effects. Miswriting a name or timestamp can backfire.
Cannot self-immortalize: The ledger will not allow edits that grant the user immortality or remove the ledger’s own costs — it enforces metaphysical limits to prevent infinite loops.
Growth Path (how the technique matures)
Novice: Footnotes and small redactions. Learning to minimize time cost via knowledge.
Intermediate: Faster addendums and marginalia contracts. Can edit sensory memories from a distance.
Advanced: Chapter Rewrites with controlled paradox: user learns to “fold” paradox into controlled constructs (e.g., create a ghost-ward).
True Potential (Extreme): The user gains limited ability to write meta-entries — edits about causality itself (e.g., “All edits made through this ledger within 10 minutes are reversible”), enabling strategic reversibility. This stage produces intense paradox and existential risk but offers near-godlike battlefield control.
Example Combat Uses (short bites)
During a hunt, erase the target’s memory of a safe path → ambush.
Bind a rogue sorcerer with a Marginalia Contract making them lose their technique if they break the pact.
Erase the existence of an explosive’s trigger by redacting the person who built it (careful—paradox!).
In a duel, rewrite the outcome of the opponent’s previous victory to have been a draw, removing their morale buff and causing psychic unravelling.