The Coven-Feud. The Ordo Hereticus keeps no peace with the psyker-cult. Wherever a Seer Council, a sorcerer cult, a Genestealer brood, or any warp-touched warband is found, the witch-hunters name it prey and hunt it to the end — there is no truce to be struck with the rot the Ordo exists to burn. While the feud stands, the Hereticus gains reputation for any battle in which it takes an enemy psyker or cult-leader Champion Out of Action, and it may declare a Coven-Purge against the feuded gang once each campaign phase. The cult is granted nothing in return; it is quarry, not a partner, and the hunt ends only when the coven is ash.
Codex · Inquisition
Alliances2
Whoany psyker-cult or heretic-coven — an Aeldari Seer Council, a Chaos sorcerer cult, a Genestealer-cult brood, or any warp-touched gang the Ordo is purpose-built to break — never a truce, always a hunt
Termsa standing campaign feud, not an alliance: the Hereticus can never make peace with a psyker-cult. While the feud holds the Hereticus gains +1 reputation for any battle in which it takes a psyker or cult-leader enemy Champion Out of Action, and may declare a Coven-Purge battle against the feuded gang once per campaign phase; the cult gains no terms in return — it is prey, not a partner
Whoanother Ordo of the Inquisition (an Ordo Malleus or Ordo Xenos warband, any pairing — never a fixed named House) that shares a hunt against a common heresy, lending tools rather than bodies
Termsa campaign-level, phase-gated shared-hunt pact: while it holds, each Ordo may lend the other ONE support-roster tool (a single fighter or a single relic) for a joint battle at cost, and both observe map-level non-aggression. No cross-Ordo fighters join a normal-battle gang list. The pact opens only at a world's incursion/purge phase and dissolves when the shared enemy is broken
The Ordo Pact. Against a shared heresy the three Ordos set aside their separate hunts and lend one another tools. The Ordo Hereticus may enter a phase-gated pact with an Ordo Malleus or Ordo Xenos warband — any pairing, never a fixed House — bound by a common enemy. While the pact holds, each Ordo may lend the other a single support-roster tool, one fighter or one relic, for a joint battle, and both observe map-level non-aggression. No cross-Ordo fighter ever joins a normal-battle gang list; the pact is a campaign compact, not a merger. It opens only at a world's incursion or purge phase, and dissolves the moment the shared enemy is broken, each Inquisitor returning to his own hunt.