OpGetCaster returns null if the caster is null.

Common/src/main/java/at/petrak/hexcasting/common/casting/operators/selectors/OpGetCaster.kt

@@ -9,6 +9,9 @@ object OpGetCaster : ConstMediaAction {
     override val argc = 0
 
     override fun execute(args: List<Iota>, ctx: CastingEnvironment): List<Iota> {
+        if (ctx.caster == null)
+            return null.asActionResult
+
         ctx.assertEntityInRange(ctx.caster)
         return ctx.caster.asActionResult
     }

Common/src/main/resources/data/hexcasting/patchouli_books/thehexbook/en_us/entries/patterns/basics.json

@@ -11,7 +11,7 @@
       "op_id": "hexcasting:get_caster",
       "anchor": "hexcasting:get_caster",
       "input": "",
-      "output": "entity",
+      "output": "entity | null",
       "text": "hexcasting.page.basics_pattern.get_caster"
     },
     {