diff --git a/CLAUDE.md b/CLAUDE.md
index a877cf3..8aef5f5 100644
--- a/CLAUDE.md
+++ b/CLAUDE.md
@@ -14,7 +14,7 @@ Game art is generated via the Gemini API (`gemini-3-pro-image-preview`, ~$0.134/
 ### Process
 1. Generate images with `curl` to `https://generativelanguage.googleapis.com/v1beta/models/gemini-3-pro-image-preview:generateContent?key=<API_KEY>`, requesting soft-shaded anime style
 2. Save responses to `/home/naomi/code/naomi/elysium/img/<category>/<id>.jpg`
-3. Upload to R2 with: `AWS_ACCESS_KEY_ID=dd0a3d73969143ada84d50f8940cc5e2 AWS_SECRET_ACCESS_KEY=f73e9907da1b2297e93e17f786d6446d33d4ac60e185879578a0d5020899b18e aws s3 sync img/ s3://nhcarrigan-cdn/elysium/ --endpoint-url https://751c386661d378cc032093493cfb0869.r2.cloudflarestorage.com`
+3. Upload to R2 with the AWS CLI — credentials are in the global `~/.claude/CLAUDE.md` (never commit them here)
 4. Delete the local `img/` directory before committing (images live on CDN only)
 
 ### CDN URL Helper
diff --git a/apps/api/src/data/upgrades.ts b/apps/api/src/data/upgrades.ts
index 6dc88e3..17fc9bc 100644
--- a/apps/api/src/data/upgrades.ts
+++ b/apps/api/src/data/upgrades.ts
@@ -767,4 +767,70 @@ export const defaultUpgrades: Array<Upgrade> = [
     target:     "adventurer",
     unlocked:   false,
   },
+  // ── Essence Sinks ─────────────────────────────────────────────────────────
+  {
+    costCrystals: 0,
+    costEssence:  1e12,
+    costGold:     0,
+    description:
+      "Channel a vast reservoir of essence into the guild's core — all production ×2.",
+    id:         "essence_sink_1",
+    multiplier: 2,
+    name:       "Essence Infusion I",
+    purchased:  false,
+    target:     "global",
+    unlocked:   true,
+  },
+  {
+    costCrystals: 0,
+    costEssence:  5e12,
+    costGold:     0,
+    description:
+      "A deeper infusion saturates every operation with raw essence — all production ×2.",
+    id:         "essence_sink_2",
+    multiplier: 2,
+    name:       "Essence Infusion II",
+    purchased:  false,
+    target:     "global",
+    unlocked:   true,
+  },
+  {
+    costCrystals: 0,
+    costEssence:  2.5e13,
+    costGold:     0,
+    description:
+      "Essence floods the ley-lines binding your guild — all production ×2.",
+    id:         "essence_sink_3",
+    multiplier: 2,
+    name:       "Essence Infusion III",
+    purchased:  false,
+    target:     "global",
+    unlocked:   true,
+  },
+  {
+    costCrystals: 0,
+    costEssence:  1e14,
+    costGold:     0,
+    description:
+      "The guild breathes essence as its very lifeblood — all production ×3.",
+    id:         "essence_sink_4",
+    multiplier: 3,
+    name:       "Essence Infusion IV",
+    purchased:  false,
+    target:     "global",
+    unlocked:   true,
+  },
+  {
+    costCrystals: 0,
+    costEssence:  5e14,
+    costGold:     0,
+    description:
+      "Essence transcends material form and reshapes reality itself — all production ×5.",
+    id:         "essence_sink_5",
+    multiplier: 5,
+    name:       "Essence Infusion V",
+    purchased:  false,
+    target:     "global",
+    unlocked:   true,
+  },
 ];
diff --git a/apps/web/src/components/game/aboutPanel.tsx b/apps/web/src/components/game/aboutPanel.tsx
index c159b37..1c5caf1 100644
--- a/apps/web/src/components/game/aboutPanel.tsx
+++ b/apps/web/src/components/game/aboutPanel.tsx
@@ -34,7 +34,10 @@ const howToPlay = [
       + " for the current run and stack multiplicatively — two ×2 upgrades"
       + " targeting the same adventurer combine to give ×4, not ×3. Global"
       + " upgrades multiply on top of adventurer-specific ones, so stacking"
-      + " both types compounds the effect significantly.",
+      + " both types compounds the effect significantly. Late in a run, look"
+      + " for the Essence Infusion upgrades — five powerful global multipliers"
+      + " purchasable purely with essence, giving that resource an ongoing"
+      + " use when gold upgrades are all bought.",
     title: "🔧 Upgrades",
   },
   {