xarrul rework

storylines/possession.md

@@ -2,7 +2,7 @@
 
 ## Overview
 
-Bren Aldara was an arcanist. Seven years ago, he studied a thin point between planes — this one, beneath the Burnt Tongue — and something latched on. **Skein**, a parasitic entity from the Ethereal Plane, attached itself to Bren's mind and has been feeding on him ever since. What the tavern patrons see as a madman talking to himself is a prisoner begging his captor for mercy.
+Bren Aldara was an arcanist. Seven years ago, he studied a thin point between planes — this one, beneath the Nether Inn — and something latched on. **Skein**, a parasitic entity from the Ethereal Plane, attached itself to Bren's mind and has been feeding on him ever since. What the tavern patrons see as a madman talking to himself is a prisoner begging his captor for mercy.
 
 This subplot is about recognizing that what looks like madness is actually captivity, and choosing whether to do anything about it.
 
@@ -55,6 +55,14 @@ Skein is not a fiend, not undead, not aberrant in the traditional sense. It's a
 
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+## DM — Bren as a Xarrul-Detector
+
+Skein is deeply afraid of Xarrul, and fear *distracts* it. When the fiend comes near, Skein's attention snaps to the bigger predator, its grip on Bren slips, and Bren surfaces. This is why his lucid windows cluster around Xarrul's presence: beyond the occasional sentence that slips past Skein's active silencing (see **Silence the Host**, above), the *deeper* lucidity comes from the parasite being too frightened to concentrate. Xarrul knows this and does **not** provoke Skein on purpose — agitating the parasite would only free the witness's tongue. But it can't help it: **its mere presence sets Skein off.**
+
+The upshot for the table: **Bren is a fiend-detector the players can learn to read.** When the madman suddenly goes rigid, stares at empty air, or snaps briefly coherent, Xarrul is near *right now* — often because it has just come close to work the room or to edit a memory (its **Waking Dream** needs line of sight; see [Xarrul — The Two Jobs](../npc/xarrul.md)). Kael witnessed this during the brawl without understanding it: Bren went stiff, staring at the bar, at the exact moment Xarrul was killing Orenn behind it. A party that clocks the pattern gains a dowsing rod for the invisible thing hunting them — and a warning that a memory near them may have just been rewritten.
+
+---
+
 ## How Players Discover the Possession
 
 ### Stage 1: Something's Off