diff --git a/Mage.Sets/src/mage/cards/a/Arboria.java b/Mage.Sets/src/mage/cards/a/Arboria.java
index bfe5a2b154..31111aa155 100644
--- a/Mage.Sets/src/mage/cards/a/Arboria.java
+++ b/Mage.Sets/src/mage/cards/a/Arboria.java
@@ -87,7 +87,7 @@ class ArboriaEffect extends RestrictionEffect {
     @Override
     public boolean canAttack(Permanent attacker, UUID defenderId, Ability source, Game game) {
         CastSpellYourLastTurnWatcher watcher = (CastSpellYourLastTurnWatcher) game.getState().getWatchers().get(CastSpellYourLastTurnWatcher.class.getSimpleName());
-        if (watcher.getAmountOfSpellsCastOnPlayersTurn(defenderId) > 0) {
+        if (watcher != null && watcher.getAmountOfSpellsCastOnPlayersTurn(defenderId) > 0) {
             return true;
         }
 
diff --git a/Mage/src/main/java/mage/watchers/common/CastSpellYourLastTurnWatcher.java b/Mage/src/main/java/mage/watchers/common/CastSpellYourLastTurnWatcher.java
index a9188dd13d..1a3ae1a5ca 100644
--- a/Mage/src/main/java/mage/watchers/common/CastSpellYourLastTurnWatcher.java
+++ b/Mage/src/main/java/mage/watchers/common/CastSpellYourLastTurnWatcher.java
@@ -27,7 +27,6 @@
  */
 package mage.watchers.common;
 
-import mage.MageObjectReference;
 import mage.constants.WatcherScope;
 import mage.game.Game;
 import mage.game.events.GameEvent;
@@ -43,7 +42,7 @@ public class CastSpellYourLastTurnWatcher extends Watcher {
 
     private final Map<UUID, Integer> amountOfSpellsCastOnPrevTurn = new HashMap<>();
     private final Map<UUID, Integer> amountOfSpellsCastOnCurrentTurn = new HashMap<>();
-    private final Map<UUID, Integer> activePlayer = new HashMap<>();
+    private UUID lastActivePlayer = null;
 
     public CastSpellYourLastTurnWatcher() {
         super(CastSpellYourLastTurnWatcher.class.getSimpleName(), WatcherScope.GAME);
@@ -61,12 +60,10 @@ public class CastSpellYourLastTurnWatcher extends Watcher {
 
     @Override
     public void watch(GameEvent event, Game game) {
-        activePlayer.clear();
-        activePlayer.putIfAbsent(game.getActivePlayerId(), 0);
+        lastActivePlayer = game.getActivePlayerId();
         if (event.getType() == GameEvent.EventType.SPELL_CAST) {
             UUID playerId = event.getPlayerId();
-            UUID activePlayerId = game.getActivePlayerId();
-            if (playerId != null && activePlayerId != null && playerId == activePlayerId) {
+            if (playerId != null && lastActivePlayer != null && playerId == lastActivePlayer) {
                 amountOfSpellsCastOnCurrentTurn.putIfAbsent(playerId, 0);
                 amountOfSpellsCastOnCurrentTurn.compute(playerId, (k, a) -> a + 1);
             }
@@ -75,16 +72,15 @@ public class CastSpellYourLastTurnWatcher extends Watcher {
 
     @Override
     public void reset() {
-        for (Entry<UUID, Integer> entry : amountOfSpellsCastOnPrevTurn.entrySet()) {
-            for (Entry<UUID, Integer> entry2 : activePlayer.entrySet()) {
-                if (entry2.getKey() == entry.getKey()) {
-                    amountOfSpellsCastOnPrevTurn.remove(entry.getKey());
-                }
-            }
+        if (amountOfSpellsCastOnPrevTurn != null
+                && lastActivePlayer != null
+                && amountOfSpellsCastOnPrevTurn.get(lastActivePlayer) != null) {
+            amountOfSpellsCastOnPrevTurn.remove(lastActivePlayer);
         }
+
         amountOfSpellsCastOnPrevTurn.putAll(amountOfSpellsCastOnCurrentTurn);
         amountOfSpellsCastOnCurrentTurn.clear();
-        activePlayer.clear();
+        lastActivePlayer = null;
     }
 
     public Integer getAmountOfSpellsCastOnPlayersTurn(UUID playerId) {
diff --git a/Mage/src/main/java/mage/watchers/common/PermanentsEnteredBattlefieldYourLastTurnWatcher.java b/Mage/src/main/java/mage/watchers/common/PermanentsEnteredBattlefieldYourLastTurnWatcher.java
index d2718d52a7..857bdd81ed 100644
--- a/Mage/src/main/java/mage/watchers/common/PermanentsEnteredBattlefieldYourLastTurnWatcher.java
+++ b/Mage/src/main/java/mage/watchers/common/PermanentsEnteredBattlefieldYourLastTurnWatcher.java
@@ -8,8 +8,6 @@ package mage.watchers.common;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
-import java.util.Map;
-import java.util.Map.Entry;
 import java.util.UUID;
 import mage.constants.WatcherScope;
 import mage.game.Game;
@@ -25,7 +23,7 @@ public class PermanentsEnteredBattlefieldYourLastTurnWatcher extends Watcher {
 
     private final HashMap<UUID, List<Permanent>> enteringBattlefield = new HashMap<>();
     private final HashMap<UUID, List<Permanent>> enteringBattlefieldLastTurn = new HashMap<>();
-    private final Map<UUID, Integer> activePlayer = new HashMap<>();
+    private UUID lastActivePlayer = null;
 
     public PermanentsEnteredBattlefieldYourLastTurnWatcher() {
         super(PermanentsEnteredBattlefieldYourLastTurnWatcher.class.getSimpleName(), WatcherScope.GAME);
@@ -44,8 +42,7 @@ public class PermanentsEnteredBattlefieldYourLastTurnWatcher extends Watcher {
 
     @Override
     public void watch(GameEvent event, Game game) {
-        activePlayer.clear();
-        activePlayer.putIfAbsent(game.getActivePlayerId(), 0);
+        lastActivePlayer = game.getActivePlayerId();
 
         if (event.getType() == GameEvent.EventType.ENTERS_THE_BATTLEFIELD) {
             Permanent perm = game.getPermanentEntering(event.getTargetId());
@@ -67,16 +64,14 @@ public class PermanentsEnteredBattlefieldYourLastTurnWatcher extends Watcher {
 
     @Override
     public void reset() {
-        for (Entry<UUID, List<Permanent>> entry : enteringBattlefieldLastTurn.entrySet()) {
-            for (Entry<UUID, Integer> entry2 : activePlayer.entrySet()) {
-                if (entry2.getKey() == entry.getKey()) {
-                    enteringBattlefieldLastTurn.remove(entry.getKey());
-                }
-            }
+        if (enteringBattlefieldLastTurn != null
+                && lastActivePlayer != null
+                && enteringBattlefieldLastTurn.get(lastActivePlayer) != null) {
+            enteringBattlefieldLastTurn.remove(lastActivePlayer);
         }
         enteringBattlefieldLastTurn.putAll(enteringBattlefield);
         enteringBattlefield.clear();
-        activePlayer.clear();
+        lastActivePlayer = null;
     }
 
     public List<Permanent> getPermanentsEnteringOnPlayersLastTurn(Game game, UUID playerId) {