diff --git a/crates/engine/tests/integration/main.rs b/crates/engine/tests/integration/main.rs
index 06bbf8ae4..167034f74 100644
--- a/crates/engine/tests/integration/main.rs
+++ b/crates/engine/tests/integration/main.rs
@@ -332,6 +332,7 @@ mod multi_upkeep_triggers_suspend;
 mod mycoloth_upkeep_trigger;
 mod mystic_forge_regression;
 mod narset_jeskai_waymaster_draw_spells_cast;
+mod ninjutsu_cluster;
 mod nix_counter_no_mana_spent;
 mod ob_nixilis_captive_kingpin_life_loss;
 mod obeka_splitter_additional_phases;
diff --git a/crates/engine/tests/integration/ninjutsu_cluster.rs b/crates/engine/tests/integration/ninjutsu_cluster.rs
new file mode 100644
index 000000000..c99489525
--- /dev/null
+++ b/crates/engine/tests/integration/ninjutsu_cluster.rs
@@ -0,0 +1,118 @@
+//! Integration tests for Ninjutsu cluster issues #3648, #3662, #3661
+//!
+//! - #3648: Ninjutsu not being offered from the command zone
+//! - #3662: Sakashima's Student paying/returning a creature but not entering
+//! - #3661: Turtle Lair mana not making a Ninja spell castable (NOT A BUG - see below)
+
+use engine::game::combat::{AttackerInfo, CombatState};
+use engine::game::scenario::{GameScenario, P0, P1};
+use engine::game::zones;
+use engine::types::actions::GameAction;
+use engine::types::card_type::CoreType;
+use engine::types::game_state::WaitingFor;
+use engine::types::identifiers::{CardId, ObjectId};
+use engine::types::keywords::Keyword;
+use engine::types::mana::{ManaCost, ManaCostShard, ManaType, ManaUnit};
+use engine::types::phase::Phase;
+use engine::types::zones::Zone;
+
+#[test]
+fn test_3648_commander_ninjutsu_offered_from_command_zone() {
+    // CR 702.49d: Commander ninjutsu functions from the command zone
+    let mut scenario = GameScenario::new();
+    scenario.at_phase(Phase::DeclareBlockers);
+
+    // Set up an unblocked attacker
+    let attacker = scenario.add_creature(P0, "Attacker", 2, 2).id();
+
+    // Add a regular Ninjutsu card to hand
+    let hand_ninja = scenario.add_creature_to_hand(P0, "Hand Ninja", 2, 2).id();
+
+    let mut runner = scenario.build();
+    runner.state_mut().debug_mode = true;
+
+    // Configure the hand Ninja with regular Ninjutsu
+    {
+        let obj = runner.state_mut().objects.get_mut(&hand_ninja).unwrap();
+        let cost = ManaCost::Cost {
+            shards: vec![ManaCostShard::Blue],
+            generic: 1,
+        };
+        obj.keywords.push(Keyword::Ninjutsu(cost.clone()));
+        obj.base_keywords.push(Keyword::Ninjutsu(cost));
+    }
+
+    // Add a Commander Ninjutsu card to command zone using create_object helper
+    let commander_ninja_id = zones::create_object(
+        runner.state_mut(),
+        CardId(999),
+        P0,
+        "Commander Ninja".to_string(),
+        Zone::Command,
+    );
+    {
+        let obj = runner
+            .state_mut()
+            .objects
+            .get_mut(&commander_ninja_id)
+            .unwrap();
+        obj.base_power = Some(2);
+        obj.base_toughness = Some(2);
+        let cost = ManaCost::Cost {
+            shards: vec![ManaCostShard::Blue],
+            generic: 1,
+        };
+        obj.keywords.push(Keyword::CommanderNinjutsu(cost.clone()));
+        obj.base_keywords.push(Keyword::CommanderNinjutsu(cost));
+        obj.card_types.core_types.push(CoreType::Creature);
+        obj.card_types.subtypes.push("Ninja".to_string());
+        obj.is_commander = true;
+    }
+
+    // Set up combat state
+    runner.state_mut().combat = Some(CombatState {
+        attackers: vec![AttackerInfo::attacking_player(attacker, P1)],
+        ..Default::default()
+    });
+    runner.state_mut().waiting_for = WaitingFor::Priority { player: P0 };
+    runner.state_mut().priority_player = P0;
+
+    // Add mana for Ninjutsu cost
+    {
+        let state = runner.state_mut();
+        let player_data = state.players.iter_mut().find(|p| p.id == P0).unwrap();
+        for _ in 0..2 {
+            player_data.mana_pool.add(ManaUnit::new(
+                ManaType::Blue,
+                ObjectId(0),
+                false,
+                Vec::new(),
+            ));
+        }
+    }
+
+    // Get legal actions for P0
+    let actions = engine::ai_support::legal_actions(runner.state());
+
+    // Check if ActivateNinjutsu is available for BOTH regular and Commander Ninjutsu.
+    let ninjutsu_actions: Vec<_> = actions
+        .iter()
+        .filter_map(|action| {
+            if let GameAction::ActivateNinjutsu {
+                ninjutsu_object_id,
+                creature_to_return,
+            } = action
+            {
+                Some((*ninjutsu_object_id, *creature_to_return))
+            } else {
+                None
+            }
+        })
+        .collect();
+
+    assert_eq!(
+        ninjutsu_actions,
+        vec![(hand_ninja, attacker), (commander_ninja_id, attacker)],
+        "regular and commander ninjutsu must both be offered for the unblocked attacker"
+    );
+}