Add poison damage over time tactics

data/defs/skills.json

@@ -79,5 +79,17 @@
     "effects": [
       { "type": "stat_bonus", "stat": "atk", "amount": -3, "duration_turns": 2 }
     ]
+  },
+  "poison_mist": {
+    "name": "Poison Mist",
+    "kind": "support",
+    "target": "enemy",
+    "mp_cost": 6,
+    "range": [1, 3],
+    "power": 0,
+    "stat": "int",
+    "effects": [
+      { "type": "damage_over_time", "status": "poison", "amount": 4, "duration_turns": 2 }
+    ]
   }
 }