diff --git a/packages/entity/src/behavior-components/expression/invocation.jsx b/packages/entity/src/behavior-components/expression/invocation.jsx
index 330a9a2..b1e1a26 100644
--- a/packages/entity/src/behavior-components/expression/invocation.jsx
+++ b/packages/entity/src/behavior-components/expression/invocation.jsx
@@ -60,9 +60,16 @@ const Invocation = ({
         />
       );
     }
-    const j = description.vararg ? Math.min(description?.args?.length - 1, i) : i;
-    const options = description?.args?.[j].options;
-    const type = description?.args?.[j].type || 'undefined';
+    let darg;
+    if ('function' === typeof description?.args) {
+      darg = description?.args(i);
+    }
+    else {
+      const j = description.vararg ? i % description?.args?.length : i;
+      darg = description?.args?.[j];
+    }
+    const {options} = darg;
+    const type = darg.type || 'undefined';
     return (
       <Variant
         context={context}
@@ -73,7 +80,7 @@ const Invocation = ({
         value={arg}
         vararg={
           'undefined' === type
-          || (description.vararg && j === description?.args?.length - 1)
+          || description.vararg
         }
       />
     );