diff --git a/crates/wasm-actor/tests/wasm_actor.rs b/crates/wasm-actor/tests/wasm_actor.rs
index ad5eaea..7e4f0d9 100644
--- a/crates/wasm-actor/tests/wasm_actor.rs
+++ b/crates/wasm-actor/tests/wasm_actor.rs
@@ -10211,4 +10211,154 @@ fn runtime_dropped_with_active_wasm_actors() {
         // rt dropped here with live actors and unprocessed responses
     }
     // No panic — wasmtime Store cleanup is safe
+}
+
+// ── Cycle 70 ─────────────────────────────────────────────────────────────────
+
+// Guest that reads i32 from payload and uses it as send count
+#[test]
+fn guest_dynamic_send_count_from_payload() {
+    let wat = r#"(module
+        (import "swactor" "send" (func $send (param i32 i32 i32)))
+        (memory (export "memory") 1)
+        (func (export "alloc") (param $len i32) (result i32) i32.const 1024)
+        (func (export "handle") (param $ptr i32) (param $len i32)
+            (local $count i32)
+            (local $i i32)
+            ;; Need at least 33 bytes: 32 dest + 1 count byte
+            (if (i32.lt_u (local.get $len) (i32.const 33)) (then return))
+            ;; Read count from byte 32
+            (local.set $count (i32.load8_u (i32.add (local.get $ptr) (i32.const 32))))
+            ;; Cap at 10 to prevent excessive sends
+            (if (i32.gt_u (local.get $count) (i32.const 10))
+                (then (local.set $count (i32.const 10)))
+            )
+            ;; Send count times (empty payload from offset 0)
+            (local.set $i (i32.const 0))
+            (block $exit
+                (loop $loop
+                    (br_if $exit (i32.ge_u (local.get $i) (local.get $count)))
+                    (call $send (local.get $ptr) (i32.const 0) (i32.const 0))
+                    (local.set $i (i32.add (local.get $i) (i32.const 1)))
+                    (br $loop)
+                )
+            )
+        )
+    )"#;
+    let engine = SharedEngine::new().unwrap();
+    let actor = WasmActorBuilder::new(engine, wat::parse_str(wat).unwrap())
+        .build().unwrap();
+    let rt = Runtime::new(RuntimeConfig::default());
+    let inbox = rt.new_inbox::<ByteMessage>().unwrap();
+    let addr = rt.spawn(actor).unwrap();
+
+    // Send with count byte = 5
+    let mut msg = Vec::new();
+    msg.extend_from_slice(&inbox.addr().0);
+    msg.push(5); // count
+    rt.send_to(addr, ByteMessage(msg)).unwrap();
+    rt.tick();
+
+    let msgs: Vec<_> = std::iter::from_fn(|| inbox.try_recv()).collect();
+    assert_eq!(msgs.len(), 5, "should send exactly 5 messages");
+}
+
+// Three actors in pipeline: A → B → C → inbox
+#[test]
+fn three_actor_pipeline() {
+    let engine = SharedEngine::new().unwrap();
+    let a = WasmActorBuilder::new(engine.clone(), guest_wasm("echo")).build().unwrap();
+    let b = WasmActorBuilder::new(engine.clone(), guest_wasm("echo")).build().unwrap();
+    let c = WasmActorBuilder::new(engine, guest_wasm("echo")).build().unwrap();
+    let rt = Runtime::new(RuntimeConfig::default());
+    let inbox = rt.new_inbox::<ByteMessage>().unwrap();
+
+    let a_addr = rt.spawn(a).unwrap();
+    let b_addr = rt.spawn(b).unwrap();
+    let c_addr = rt.spawn(c).unwrap();
+
+    // A echoes to B, B echoes to C, C echoes to inbox
+    // But we need to set dest addresses in each message frame:
+    // Send to A with dest=B, payload that contains framed(C, framed(inbox, "hi"))
+    // Actually echo just echoes the payload portion to the dest — so:
+    // A receives: [B_addr][C_addr][inbox_addr]"hi" → sends [C_addr][inbox_addr]"hi" to B
+    // B receives: [C_addr][inbox_addr]"hi" → sends [inbox_addr]"hi" to C
+    // C receives: [inbox_addr]"hi" → sends "hi" to inbox
+    let mut payload = Vec::new();
+    payload.extend_from_slice(&c_addr.0);
+    payload.extend_from_slice(&inbox.addr().0);
+    payload.extend_from_slice(b"hi");
+
+    rt.send_to(a_addr, framed_msg(&b_addr, &payload)).unwrap();
+    rt.tick(); // A → B
+    rt.tick(); // B → C
+    rt.tick(); // C → inbox
+
+    let resp = inbox.try_recv().expect("message should traverse 3-hop pipeline");
+    assert_eq!(resp.0, b"hi");
+}
+
+// Build actors from 3 different guest types in tight loop
+#[test]
+fn rapid_build_three_guest_types() {
+    let engine = SharedEngine::new().unwrap();
+    let echo_bytes = guest_wasm("echo");
+    let double_bytes = guest_wasm("double");
+    let silent_bytes = guest_wasm("silent");
+
+    for _ in 0..20 {
+        let _ = WasmActorBuilder::new(engine.clone(), echo_bytes.clone()).build().unwrap();
+        let _ = WasmActorBuilder::new(engine.clone(), double_bytes.clone()).build().unwrap();
+        let _ = WasmActorBuilder::new(engine.clone(), silent_bytes.clone()).build().unwrap();
+    }
+    // 60 build+drop cycles — no leaks, no panics
+}
+
+// Guest with i32.xor instruction
+#[test]
+fn guest_xor_payload_with_key() {
+    let wat = r#"(module
+        (import "swactor" "send" (func $send (param i32 i32 i32)))
+        (memory (export "memory") 1)
+        (func (export "alloc") (param $len i32) (result i32) i32.const 1024)
+        (func (export "handle") (param $ptr i32) (param $len i32)
+            (local $i i32)
+            ;; Need >= 33 bytes: 32 dest + at least 1 payload
+            (if (i32.lt_u (local.get $len) (i32.const 33)) (then return))
+            ;; XOR each payload byte with 0xFF
+            (local.set $i (i32.const 32))
+            (block $exit
+                (loop $loop
+                    (br_if $exit (i32.ge_u (local.get $i) (local.get $len)))
+                    (i32.store8
+                        (i32.add (local.get $ptr) (local.get $i))
+                        (i32.xor
+                            (i32.load8_u (i32.add (local.get $ptr) (local.get $i)))
+                            (i32.const 0xFF)
+                        )
+                    )
+                    (local.set $i (i32.add (local.get $i) (i32.const 1)))
+                    (br $loop)
+                )
+            )
+            ;; Send XORed payload
+            (call $send
+                (local.get $ptr)
+                (i32.add (local.get $ptr) (i32.const 32))
+                (i32.sub (local.get $len) (i32.const 32))
+            )
+        )
+    )"#;
+    let engine = SharedEngine::new().unwrap();
+    let actor = WasmActorBuilder::new(engine, wat::parse_str(wat).unwrap())
+        .build().unwrap();
+    let rt = Runtime::new(RuntimeConfig::default());
+    let inbox = rt.new_inbox::<ByteMessage>().unwrap();
+    let addr = rt.spawn(actor).unwrap();
+
+    rt.send_to(addr, framed_msg(inbox.addr(), &[0x00, 0xFF, 0xAA])).unwrap();
+    rt.tick();
+
+    let resp = inbox.try_recv().expect("XOR response");
+    assert_eq!(resp.0, vec![0xFF, 0x00, 0x55], "each byte XORed with 0xFF");
 }
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