[DFT] Implement Riverchurn Monument (#13405)

* fix MillCardsTargetEffect to work with multiple targets

Mage.Sets/src/mage/cards/r/RiverchurnMonument.java

@@ -0,0 +1,88 @@
+package mage.cards.r;
+
+import java.util.UUID;
+
+import mage.abilities.Ability;
+import mage.abilities.common.SimpleActivatedAbility;
+import mage.abilities.costs.common.TapSourceCost;
+import mage.abilities.costs.mana.ManaCostsImpl;
+import mage.abilities.effects.Effect;
+import mage.abilities.effects.OneShotEffect;
+import mage.abilities.effects.common.MillCardsTargetEffect;
+import mage.abilities.keyword.ExhaustAbility;
+import mage.cards.CardImpl;
+import mage.cards.CardSetInfo;
+import mage.constants.CardType;
+import mage.constants.Outcome;
+import mage.game.Game;
+import mage.players.Player;
+import mage.target.TargetPlayer;
+import mage.target.targetpointer.EachTargetPointer;
+
+/**
+ *
+ * @author Jmlundeen
+ */
+public final class RiverchurnMonument extends CardImpl {
+
+    public RiverchurnMonument(UUID ownerId, CardSetInfo setInfo) {
+        super(ownerId, setInfo, new CardType[]{CardType.ARTIFACT}, "{1}{U}");
+        
+
+        // {1}, {T}: Any number of target players each mill two cards.
+        Effect effect = new MillCardsTargetEffect(2);
+        effect.setTargetPointer(new EachTargetPointer());
+        effect.setText("Any number of target players each mill two cards. " +
+                "(Each of them puts the top two cards of their library into their graveyard.)");
+        Ability ability = new SimpleActivatedAbility(effect, new ManaCostsImpl<>("{1}"));
+        ability.addCost(new TapSourceCost());
+        ability.addTarget(new TargetPlayer(0, Integer.MAX_VALUE, false));
+        this.addAbility(ability);
+
+        // Exhaust -- {2}{U}{U}, {T}: Any number of target players each mill cards equal to the number of cards in their graveyard.
+        Effect exhaustEffect = new RiverchurnMonumentEffect();
+        exhaustEffect.setTargetPointer(new EachTargetPointer());
+        exhaustEffect.setText("Any number of target players each mill cards equal to the number of cards in their graveyard.");
+        Ability exhaustAbility = new ExhaustAbility(exhaustEffect, new ManaCostsImpl<>("{2}{U}{U}"));
+        exhaustAbility.addCost(new TapSourceCost());
+        exhaustAbility.addTarget(new TargetPlayer(0, Integer.MAX_VALUE, false));
+        this.addAbility(exhaustAbility);
+    }
+
+    private RiverchurnMonument(final RiverchurnMonument card) {
+        super(card);
+    }
+
+    @Override
+    public RiverchurnMonument copy() {
+        return new RiverchurnMonument(this);
+    }
+}
+
+class RiverchurnMonumentEffect extends OneShotEffect {
+
+    public RiverchurnMonumentEffect() {
+        super(Outcome.Detriment);
+        this.staticText = "Any number of target players each mill cards equal to the number of cards in their graveyard.";
+    }
+
+    public RiverchurnMonumentEffect(final RiverchurnMonumentEffect effect) {
+        super(effect);
+    }
+
+    @Override
+    public RiverchurnMonumentEffect copy() {
+        return new RiverchurnMonumentEffect(this);
+    }
+
+    @Override
+    public boolean apply(Game game, Ability source) {
+        for (UUID playerId : getTargetPointer().getTargets(game, source)) {
+            Player player = game.getPlayer(playerId);
+            if (player != null) {
+                player.millCards(player.getGraveyard().size(), source, game);
+            }
+        }
+        return true;
+    }
+}

Mage.Sets/src/mage/sets/Aetherdrift.java

@@ -228,6 +228,9 @@ public final class Aetherdrift extends ExpansionSet {
         cards.add(new SetCardInfo("Rise from the Wreck", 178, Rarity.UNCOMMON, mage.cards.r.RiseFromTheWreck.class));
         cards.add(new SetCardInfo("Risen Necroregent", 102, Rarity.UNCOMMON, mage.cards.r.RisenNecroregent.class));
         cards.add(new SetCardInfo("Risky Shortcut", 103, Rarity.COMMON, mage.cards.r.RiskyShortcut.class));
+        cards.add(new SetCardInfo("Riverchurn Monument", 57, Rarity.RARE, mage.cards.r.RiverchurnMonument.class, NON_FULL_USE_VARIOUS));
+        cards.add(new SetCardInfo("Riverchurn Monument", 381, Rarity.RARE, mage.cards.r.RiverchurnMonument.class, NON_FULL_USE_VARIOUS));
+        cards.add(new SetCardInfo("Riverchurn Monument", 440, Rarity.RARE, mage.cards.r.RiverchurnMonument.class, NON_FULL_USE_VARIOUS));
         cards.add(new SetCardInfo("Riverpyre Verge", 260, Rarity.RARE, mage.cards.r.RiverpyreVerge.class));
         cards.add(new SetCardInfo("Road Rage", 145, Rarity.UNCOMMON, mage.cards.r.RoadRage.class));
         cards.add(new SetCardInfo("Roadside Assistance", 26, Rarity.UNCOMMON, mage.cards.r.RoadsideAssistance.class));

Mage/src/main/java/mage/abilities/effects/common/MillCardsTargetEffect.java

@@ -10,6 +10,8 @@ import mage.game.Game;
 import mage.players.Player;
 import mage.util.CardUtil;
 
+import java.util.UUID;
+
 /**
  * @author LevelX2
  */
@@ -38,12 +40,13 @@ public class MillCardsTargetEffect extends OneShotEffect {
 
     @Override
     public boolean apply(Game game, Ability source) {
-        Player player = game.getPlayer(getTargetPointer().getFirst(game, source));
-        if (player != null) {
-            player.millCards(numberCards.calculate(game, source, this), source, game);
-            return true;
+        for (UUID playerId : getTargetPointer().getTargets(game, source)) {
+            Player player = game.getPlayer(playerId);
+            if (player != null) {
+                player.millCards(numberCards.calculate(game, source, this), source, game);
+            }
         }
-        return false;
+        return true;
     }
 
     @Override