#Boundary Reference — Relationship with co·ex2

Contents

Canon — Boundary Protocol. This document clarifies how the divinity rules of fc01 meet the existing gods and spiritual beings of co and the expansion elements of ex2. On conflict, the principle is consistent: co Canon is immutable · only the interior of fc01 is Canon · ex2 is compatible.

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#1. Boundaries with Existing Beings in co

#Arahitogami (現人神)

• Identity: a god who has taken on a human body. The rank 10 class line of co. Details: co-04-character/co-04-05-prestige.md.
• Relationship with Shinseiki:
• The main channel through which a god acts. Making protagonist-tier divinities and main NPC gods of a campaign arahitogami is the standard.
• The most typical host for placing divinity. An arahitogami rank 10 + Imperial God grade 5 combination is the standard for an Imperial God.
• The arahitogami has "personhood," and divinity is "authority." They are most dimensional when together.
• Caution:
• The arahitogami class alone already allows transcendent-level checks. The campaign runs even without placing divinity on it.
• Divinity is placed only on a god with a clear domain. Mechanical assignment of the kind "the class is arahitogami, so it must have divinity too" is forbidden.

#Tatarigami (祟神)

• Identity: a being that became a divinity when grudge · greed · obsession warped it. A wrathful god. Details: co-04-character/co-04-07-classes/co-04-07-27-villain-tatarigami.md.
• Relationship with Shinseiki:
• Divinity is unaffected by a class transition. Even if the class changes from arahitogami → Tatarigami, the divinity grade · domain are maintained.
• However, the domain "flips." As in "grain" → "rotting of grain," "healing" → "worsening of wounds."
• A Tatarigami transition is a narrative event, not a check (in both the divinity rules and the class rules).
• Example:
• Inari transitions to Tatarigami through betrayal · lack of offerings → the domain "grain" becomes "starvation."
• Even in the transitioned state, the divinity grade remains 4 (Great God).
• Resolution:
• Follow co's Tatarigami resolution rules (purification · sealing · releasing the grudge) as written.
• Shinseiki provides an Izanagi-line Misogi Sorcery as an additional option (fc01-04-00-divine-regalia-and-rites.md).

#Celestial (天人)

• Identity: one from the celestial realm, or one who conveys the will of Heaven. The rank 10 class line of co. Details: co-04-character/co-04-07-classes/co-04-07-34-outsider-celestial.md.
• Relationship with Shinseiki:
• The natural host of divinity, next after the arahitogami. Especially suited to Imperial God · Great God line shards.
• Because the celestial has the nature of "ascension," divinity once placed does not easily fall away.
• Example:
• A miko who received a shard of Amaterasu operates as a celestial rank 10 + Divinity 4.
• One who inherited the bloodline of Ninigi is a celestial rank 8 + Divinity 3.

#Heroic Spirit (英霊)

• Identity: a state in which a dead person's will remains and holds power. Details: co-04-character/co-04-07-classes/co-04-07-33-outsider-heroic-spirit.md.
• Relationship with Shinseiki:
• In principle, a heroic spirit is not a god. Granting divinity is forbidden.
• Exception — an enshrined (祭神化) heroic spirit: a dead hero · scholar · sage elevated to divinity through the offerings of the populace · court. Only in this case may divinity be placed.
• Upper limit of elevation grade: up to Divinity 3 (Middle God). Elevation to Great God · Imperial God is almost nonexistent.
• Example:
• Sugawara no Michizane (9th century) → heroic spirit → Tenjin (Middle God 3).
• Emperor Ojin → heroic spirit → Hachiman (Great God 4, though this is a historically special case).
• Conditions for enshrinement:
• Substantial offerings by the populace · court and the building of a shrine.
• A heroic spirit that became a self-proclaimed "god" without enshrinement is highly likely to be a Tatarigami.

#Myth-Tier Yoma

• Identity: Yamata no Orochi · Jormungandr · Fenrir, and the like. Beings on the scale of a single "scenario obstacle."
• Relationship with Shinseiki:
• Statting them out in Shinseiki is forbidden (fc01-99-02-not-in-scope.md).
• That said, if these are "enshrined," they may be handled differently — but that is not within the scope of this supplement.
• How to handle them:
• Myth-tier yoma already in co are used by those rules as written.
• They will be handled as a set with a scenario in a future fcNN scenario pack.

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#2. ex2 Compatibility Memo

#Alternative Class Techniques · Alternative Backgrounds · Additional General Techniques

• Apply the divinity rules as written to characters using ex2's alternative · additional techniques · backgrounds as well.
• Example: a samurai who chose an alternative samurai technique from ex2-01-class-alt-techniques + Divinity 2 — no problem.
• When a technique and a Divine Authority give an effect of the same name at the same time, per co-99-meta/co-99-02-core-principles.md#principle-1--source-independence-and-non-stacking-of-same-name, apply only the one that is more favorable.

#ex2's Mystical Schools

• ex2-19-mystical-schools (Sorcery · Exorcism · Medicine · Barrier · Prophecy · Poisoncraft) are class skills.
• They may overlap with a Divine Authority's domain. Example: Inari's "Change" domain vs ex2's "shapeshifting art" school.
• Conflict resolution:
• Apply only one of the two to 1 check.
• The higher precedence (divinity grade vs school rank) takes priority.
• ex2's Barrier formulas and the like can aid a shrine's re-manifestation check (GM's discretion).

#ex2's Foreign Divine Treasures

• ex2-45-foreign-relics covers Western Divine Treasures such as Excalibur · Durendal · Gungnir.
• This supplement does not redefine that area. This supplement's "Outside Divine Treasures" (fc01-04-00-divine-regalia-and-rites.md) contains only what is not in ex2.
• Mutual compatibility: if one who holds Gungnir (ex2) also holds a shard of Odin (fc01), the effects can stack (excluding same-name effects).

#ex2's Era-Transcending · Foreign Schools

• ex2's school types "foreign-style (異国流)" · "era-transcending" fit this supplement well.
• A character who chose an Outside deity (e.g., a samurai who made a contract with Odin) can have ex2's Norse · Mongol schools placed on them.
• When the cultural origin of each foreign-style school matches the cultural origin of the Outside deity, it is good for synergy staging (there is no mechanical bonus — it is for narration).

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#3. Usage Priority Table

A table for the GM to reference which expression to choose per scene.

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#4. Resolution Order on Authority Conflict

1. co Canon — takes priority unconditionally.
2. ex Canon (within the relevant ex) — takes priority if that ex is in use.
3. fc01 Canon — Canon only within fc01. A Variant when referenced externally.
4. GM's discretion — when the three steps above are a gray zone.

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#In One Sentence

"Shinseiki is a garden that grows only within the fence of the main work. It does not push the fence outward."