diff --git a/Mage.Sets/src/mage/cards/s/ShadowOfTheSecondSun.java b/Mage.Sets/src/mage/cards/s/ShadowOfTheSecondSun.java
new file mode 100644
index 00000000000..8ab87b7d237
--- /dev/null
+++ b/Mage.Sets/src/mage/cards/s/ShadowOfTheSecondSun.java
@@ -0,0 +1,75 @@
+package mage.cards.s;
+
+import mage.abilities.Ability;
+import mage.abilities.common.BeginningOfPostCombatMainTriggeredAbility;
+import mage.abilities.effects.OneShotEffect;
+import mage.abilities.effects.common.AttachEffect;
+import mage.abilities.keyword.EnchantAbility;
+import mage.cards.CardImpl;
+import mage.cards.CardSetInfo;
+import mage.constants.*;
+import mage.game.Game;
+import mage.game.turn.TurnMod;
+import mage.target.TargetPlayer;
+
+import java.util.UUID;
+
+/**
+ * @author Susucr
+ */
+public final class ShadowOfTheSecondSun extends CardImpl {
+
+    public ShadowOfTheSecondSun(UUID ownerId, CardSetInfo setInfo) {
+        super(ownerId, setInfo, new CardType[]{CardType.ENCHANTMENT}, "{4}{U}{U}");
+
+        this.subtype.add(SubType.AURA);
+
+        // Enchant player
+        TargetPlayer auraTarget = new TargetPlayer();
+        this.getSpellAbility().addTarget(auraTarget);
+        this.getSpellAbility().addEffect(new AttachEffect(Outcome.Benefit));
+        this.addAbility(new EnchantAbility(auraTarget));
+
+        // At the beginning of enchanted player's postcombat main phase, there is an additional beginning phase after this phase.
+        this.addAbility(new BeginningOfPostCombatMainTriggeredAbility(
+                new ShadowOfTheSecondSunTargetEffect(),
+                TargetController.ENCHANTED, false
+        ));
+    }
+
+    private ShadowOfTheSecondSun(final ShadowOfTheSecondSun card) {
+        super(card);
+    }
+
+    @Override
+    public ShadowOfTheSecondSun copy() {
+        return new ShadowOfTheSecondSun(this);
+    }
+}
+
+class ShadowOfTheSecondSunTargetEffect extends OneShotEffect {
+
+    ShadowOfTheSecondSunTargetEffect() {
+        super(Outcome.Benefit);
+        this.staticText = "there is an additional beginning phase after this phase";
+    }
+
+    private ShadowOfTheSecondSunTargetEffect(final ShadowOfTheSecondSunTargetEffect effect) {
+        super(effect);
+    }
+
+    @Override
+    public ShadowOfTheSecondSunTargetEffect copy() {
+        return new ShadowOfTheSecondSunTargetEffect(this);
+    }
+
+    @Override
+    public boolean apply(Game game, Ability source) {
+        UUID playerId = this.getTargetPointer().getFirst(game, source);
+        if (playerId == null) {
+            return false;
+        }
+        game.getState().getTurnMods().add(new TurnMod(playerId).withExtraPhase(TurnPhase.BEGINNING));
+        return true;
+    }
+}
\ No newline at end of file
diff --git a/Mage.Sets/src/mage/sets/ModernHorizons3.java b/Mage.Sets/src/mage/sets/ModernHorizons3.java
index ec12a92d676..3d5f04f5dc0 100644
--- a/Mage.Sets/src/mage/sets/ModernHorizons3.java
+++ b/Mage.Sets/src/mage/sets/ModernHorizons3.java
@@ -240,6 +240,7 @@ public final class ModernHorizons3 extends ExpansionSet {
         cards.add(new SetCardInfo("Seething Landscape", 225, Rarity.COMMON, mage.cards.s.SeethingLandscape.class));
         cards.add(new SetCardInfo("Serum Visionary", 69, Rarity.COMMON, mage.cards.s.SerumVisionary.class));
         cards.add(new SetCardInfo("Sevinne's Reclamation", 267, Rarity.RARE, mage.cards.s.SevinnesReclamation.class));
+        cards.add(new SetCardInfo("Shadow of the Second Sun", 70, Rarity.MYTHIC, mage.cards.s.ShadowOfTheSecondSun.class));
         cards.add(new SetCardInfo("Shattered Landscape", 226, Rarity.COMMON, mage.cards.s.ShatteredLandscape.class));
         cards.add(new SetCardInfo("Sheltering Landscape", 227, Rarity.COMMON, mage.cards.s.ShelteringLandscape.class));
         cards.add(new SetCardInfo("Shifting Woodland", 228, Rarity.RARE, mage.cards.s.ShiftingWoodland.class));
diff --git a/Mage/src/main/java/mage/abilities/common/BeginningOfPostCombatMainTriggeredAbility.java b/Mage/src/main/java/mage/abilities/common/BeginningOfPostCombatMainTriggeredAbility.java
index db5de5e3c05..db6062e187d 100644
--- a/Mage/src/main/java/mage/abilities/common/BeginningOfPostCombatMainTriggeredAbility.java
+++ b/Mage/src/main/java/mage/abilities/common/BeginningOfPostCombatMainTriggeredAbility.java
@@ -6,6 +6,7 @@ import mage.constants.TargetController;
 import mage.constants.Zone;
 import mage.game.Game;
 import mage.game.events.GameEvent;
+import mage.game.permanent.Permanent;
 import mage.target.targetpointer.FixedTarget;
 
 /**
@@ -73,6 +74,15 @@ public class BeginningOfPostCombatMainTriggeredAbility extends TriggeredAbilityI
                     }
                 }
                 return true;
+            case ENCHANTED:
+                Permanent permanent = getSourcePermanentIfItStillExists(game);
+                if (permanent == null || !game.isActivePlayer(permanent.getAttachedTo())) {
+                    break;
+                }
+                if (getTargets().isEmpty()) {
+                    this.getEffects().setTargetPointer(new FixedTarget(event.getPlayerId()));
+                }
+                return true;
         }
         return false;
     }
@@ -85,6 +95,8 @@ public class BeginningOfPostCombatMainTriggeredAbility extends TriggeredAbilityI
                 return "At the beginning of each opponent's postcombat main phase, " + generateZoneString();
             case ANY:
                 return "At the beginning of each player's postcombat main phase, " + generateZoneString();
+            case ENCHANTED:
+                return "At the beginning of enchanted player's postcombat main phase, " + generateZoneString();
         }
         return "";
     }