diff --git a/Mage.Sets/src/mage/cards/f/FrodoBaggins.java b/Mage.Sets/src/mage/cards/f/FrodoBaggins.java
index c96a9c2f6a2..70f84161b84 100644
--- a/Mage.Sets/src/mage/cards/f/FrodoBaggins.java
+++ b/Mage.Sets/src/mage/cards/f/FrodoBaggins.java
@@ -10,6 +10,7 @@ import mage.abilities.effects.keyword.TheRingTemptsYouEffect;
 import mage.cards.CardImpl;
 import mage.cards.CardSetInfo;
 import mage.constants.CardType;
+import mage.constants.Duration;
 import mage.constants.SubType;
 import mage.constants.SuperType;
 import mage.filter.FilterPermanent;
@@ -44,7 +45,7 @@ public final class FrodoBaggins extends CardImpl {
 
         // As long as Frodo is your Ring-bearer, it must be blocked if able.
         this.addAbility(new SimpleStaticAbility(new ConditionalRequirementEffect(
-                new MustBeBlockedByAtLeastOneSourceEffect(), SourceIsRingBearerCondition.instance,
+                new MustBeBlockedByAtLeastOneSourceEffect(Duration.WhileOnBattlefield), SourceIsRingBearerCondition.instance,
                 "as long as {this} is your Ring-bearer, it must be blocked if able"
         )));
     }
diff --git a/Mage.Sets/src/mage/cards/h/HolgaRelentlessRager.java b/Mage.Sets/src/mage/cards/h/HolgaRelentlessRager.java
index acbd98ba181..3f59be34007 100644
--- a/Mage.Sets/src/mage/cards/h/HolgaRelentlessRager.java
+++ b/Mage.Sets/src/mage/cards/h/HolgaRelentlessRager.java
@@ -39,7 +39,7 @@ public final class HolgaRelentlessRager extends CardImpl {
         this.addAbility(HasteAbility.getInstance());
 
         // Holga, Relentless Rager must be blocked if able.
-        this.addAbility(new SimpleStaticAbility(new MustBeBlockedByAtLeastOneSourceEffect()));
+        this.addAbility(new SimpleStaticAbility(new MustBeBlockedByAtLeastOneSourceEffect(Duration.WhileOnBattlefield)));
 
         // Whenever Holga attacks, each creature you control attacking a player gets +1/+0 until end of turn for each creature that player controls.
         this.addAbility(new AttacksTriggeredAbility(new HolgaRelentlessRagerEffect()));
diff --git a/Mage.Sets/src/mage/cards/l/LoathsomeCatoblepas.java b/Mage.Sets/src/mage/cards/l/LoathsomeCatoblepas.java
index 9e314fe77dc..df1539337ae 100644
--- a/Mage.Sets/src/mage/cards/l/LoathsomeCatoblepas.java
+++ b/Mage.Sets/src/mage/cards/l/LoathsomeCatoblepas.java
@@ -1,7 +1,5 @@
-
 package mage.cards.l;
 
-import java.util.UUID;
 import mage.MageInt;
 import mage.abilities.Ability;
 import mage.abilities.common.DiesSourceTriggeredAbility;
@@ -12,34 +10,33 @@ import mage.abilities.effects.common.continuous.BoostTargetEffect;
 import mage.cards.CardImpl;
 import mage.cards.CardSetInfo;
 import mage.constants.CardType;
-import mage.constants.SubType;
 import mage.constants.Duration;
-import mage.constants.Zone;
-import mage.filter.StaticFilters;
-import mage.target.Target;
-import mage.target.common.TargetCreaturePermanent;
+import mage.constants.SubType;
+import mage.target.common.TargetOpponentsCreaturePermanent;
+
+import java.util.UUID;
 
 /**
- *
  * @author LevelX2
  */
 public final class LoathsomeCatoblepas extends CardImpl {
 
     public LoathsomeCatoblepas(UUID ownerId, CardSetInfo setInfo) {
-        super(ownerId,setInfo,new CardType[]{CardType.CREATURE},"{5}{B}");
+        super(ownerId, setInfo, new CardType[]{CardType.CREATURE}, "{5}{B}");
         this.subtype.add(SubType.BEAST);
 
         this.power = new MageInt(3);
         this.toughness = new MageInt(3);
 
         // {2}{G}: Loathsome Catoblepas must be blocked this turn if able.
-        this.addAbility(new SimpleActivatedAbility(Zone.BATTLEFIELD, new MustBeBlockedByAtLeastOneSourceEffect(), new ManaCostsImpl<>("{2}{G}")));
-        // When Loathsome Catoblepas dies, target creature an opponent controls gets -3/-3 until end of turn.
-        Ability ability = new DiesSourceTriggeredAbility(new BoostTargetEffect(-3,-3, Duration.EndOfTurn), false);
-        Target target = new TargetCreaturePermanent(StaticFilters.FILTER_OPPONENTS_PERMANENT_CREATURE);
-        ability.addTarget(target);
-        this.addAbility(ability);
+        this.addAbility(new SimpleActivatedAbility(
+                new MustBeBlockedByAtLeastOneSourceEffect(Duration.EndOfTurn), new ManaCostsImpl<>("{2}{G}")
+        ));
 
+        // When Loathsome Catoblepas dies, target creature an opponent controls gets -3/-3 until end of turn.
+        Ability ability = new DiesSourceTriggeredAbility(new BoostTargetEffect(-3, -3));
+        ability.addTarget(new TargetOpponentsCreaturePermanent());
+        this.addAbility(ability);
     }
 
     private LoathsomeCatoblepas(final LoathsomeCatoblepas card) {
diff --git a/Mage/src/main/java/mage/abilities/effects/common/combat/MustBeBlockedByAtLeastOneSourceEffect.java b/Mage/src/main/java/mage/abilities/effects/common/combat/MustBeBlockedByAtLeastOneSourceEffect.java
index 7375856341d..406818da2ae 100644
--- a/Mage/src/main/java/mage/abilities/effects/common/combat/MustBeBlockedByAtLeastOneSourceEffect.java
+++ b/Mage/src/main/java/mage/abilities/effects/common/combat/MustBeBlockedByAtLeastOneSourceEffect.java
@@ -1,19 +1,20 @@
 
 package mage.abilities.effects.common.combat;
 
-import java.util.UUID;
 import mage.abilities.Ability;
 import mage.abilities.effects.RequirementEffect;
 import mage.constants.Duration;
 import mage.game.Game;
 import mage.game.permanent.Permanent;
 
+import java.util.UUID;
+
 /**
  * http://tappedout.net/mtg-questions/must-be-blocked-if-able-effect-makes-other-attacking-creatures-essentially-unblockable/
- *
+ * <p>
  * When you Declare Blockers, you choose an arrangement for your blockers, then
  * check to see if there are any restrictions or requirements.
- *
+ * <p>
  * If any restrictions are violated, the block is illegal. (For example, trying
  * to block with Sightless Ghoul) If any requirements are violated, the least
  * possible number of requirements must be violated, otherwise the block is
@@ -35,12 +36,8 @@ import mage.game.permanent.Permanent;
  * @author LevelX2
  */
 public class MustBeBlockedByAtLeastOneSourceEffect extends RequirementEffect {
-    
-    private int minNumberOfBlockers;
 
-    public MustBeBlockedByAtLeastOneSourceEffect() {
-        this(Duration.EndOfTurn);
-    }
+    private int minNumberOfBlockers;
 
     public MustBeBlockedByAtLeastOneSourceEffect(Duration duration) {
         this(duration, 1);