diff --git a/Mage.Sets/src/mage/cards/k/KarnLegacyReforged.java b/Mage.Sets/src/mage/cards/k/KarnLegacyReforged.java
new file mode 100644
index 00000000000..0868ce1bacc
--- /dev/null
+++ b/Mage.Sets/src/mage/cards/k/KarnLegacyReforged.java
@@ -0,0 +1,124 @@
+package mage.cards.k;
+
+import mage.MageInt;
+import mage.MageObject;
+import mage.Mana;
+import mage.abilities.Ability;
+import mage.abilities.common.BeginningOfUpkeepTriggeredAbility;
+import mage.abilities.common.SimpleStaticAbility;
+import mage.abilities.dynamicvalue.DynamicValue;
+import mage.abilities.effects.Effect;
+import mage.abilities.effects.OneShotEffect;
+import mage.abilities.effects.common.continuous.SetBasePowerToughnessSourceEffect;
+import mage.abilities.mana.builder.ConditionalManaBuilder;
+import mage.cards.CardImpl;
+import mage.cards.CardSetInfo;
+import mage.constants.*;
+import mage.filter.StaticFilters;
+import mage.game.Game;
+import mage.game.permanent.token.PowerstoneToken;
+import mage.players.Player;
+
+import java.util.UUID;
+
+/**
+ * @author TheElk801
+ */
+public final class KarnLegacyReforged extends CardImpl {
+
+    public KarnLegacyReforged(UUID ownerId, CardSetInfo setInfo) {
+        super(ownerId, setInfo, new CardType[]{CardType.ARTIFACT, CardType.CREATURE}, "{5}");
+
+        this.addSuperType(SuperType.LEGENDARY);
+        this.subtype.add(SubType.GOLEM);
+        this.power = new MageInt(0);
+        this.toughness = new MageInt(0);
+
+        // Karn, Legacy Reforged's power and toughness are each equal to the greatest mana value among artifacts you control.
+        this.addAbility(new SimpleStaticAbility(
+                Zone.ALL, new SetBasePowerToughnessSourceEffect(KarnLegacyReforgedValue.instance)
+                .setText("{this}'s power and toughness are each equal to the greatest mana value among artifacts you control")
+        ));
+
+        // At the beginning of your upkeep, add {C} for each artifact you control. This mana can't be spent to cast nonartifact spells. Until end of turn, you don't lose this mana as steps and phases end.
+        this.addAbility(new BeginningOfUpkeepTriggeredAbility(
+                new KarnLegacyReforgedEffect(), TargetController.YOU, false
+        ));
+    }
+
+    private KarnLegacyReforged(final KarnLegacyReforged card) {
+        super(card);
+    }
+
+    @Override
+    public KarnLegacyReforged copy() {
+        return new KarnLegacyReforged(this);
+    }
+}
+
+enum KarnLegacyReforgedValue implements DynamicValue {
+    instance;
+
+    @Override
+    public int calculate(Game game, Ability sourceAbility, Effect effect) {
+        return game
+                .getBattlefield()
+                .getActivePermanents(
+                        StaticFilters.FILTER_CONTROLLED_PERMANENT_ARTIFACT,
+                        sourceAbility.getControllerId(), sourceAbility, game
+                )
+                .stream()
+                .mapToInt(MageObject::getManaValue)
+                .max()
+                .orElse(0);
+    }
+
+    @Override
+    public KarnLegacyReforgedValue copy() {
+        return this;
+    }
+
+    @Override
+    public String getMessage() {
+        return "";
+    }
+
+    @Override
+    public String toString() {
+        return "1";
+    }
+}
+
+class KarnLegacyReforgedEffect extends OneShotEffect {
+
+    KarnLegacyReforgedEffect() {
+        super(Outcome.Benefit);
+        staticText = "add {C} for each artifact you control. This mana can't be spent " +
+                "to cast nonartifact spells. Until end of turn, you don't lose this mana as steps and phases end";
+    }
+
+    private KarnLegacyReforgedEffect(final KarnLegacyReforgedEffect effect) {
+        super(effect);
+    }
+
+    @Override
+    public KarnLegacyReforgedEffect copy() {
+        return new KarnLegacyReforgedEffect(this);
+    }
+
+    @Override
+    public boolean apply(Game game, Ability source) {
+        Player player = game.getPlayer(source.getControllerId());
+        int artifacts = game.getBattlefield().count(
+                StaticFilters.FILTER_CONTROLLED_PERMANENT_ARTIFACT,
+                source.getControllerId(), source, game
+        );
+        if (player == null || artifacts < 1) {
+            return false;
+        }
+        ConditionalManaBuilder builder = PowerstoneToken.makeBuilder();
+        builder.setMana(Mana.ColorlessMana(artifacts), source, game);
+        player.getManaPool().addMana(builder.build(), game, source, true);
+        return true;
+    }
+}
diff --git a/Mage.Sets/src/mage/sets/MarchOfTheMachineTheAftermath.java b/Mage.Sets/src/mage/sets/MarchOfTheMachineTheAftermath.java
index 0065078ea33..3e11f96971d 100644
--- a/Mage.Sets/src/mage/sets/MarchOfTheMachineTheAftermath.java
+++ b/Mage.Sets/src/mage/sets/MarchOfTheMachineTheAftermath.java
@@ -28,6 +28,7 @@ public final class MarchOfTheMachineTheAftermath extends ExpansionSet {
         cards.add(new SetCardInfo("Gold-Forged Thopteryx", 31, Rarity.UNCOMMON, mage.cards.g.GoldForgedThopteryx.class));
         cards.add(new SetCardInfo("Harnessed Snubhorn", 3, Rarity.UNCOMMON, mage.cards.h.HarnessedSnubhorn.class));
         cards.add(new SetCardInfo("Jolrael, Voice of Zhalfir", 33, Rarity.RARE, mage.cards.j.JolraelVoiceOfZhalfir.class));
+        cards.add(new SetCardInfo("Karn, Legacy Reforged", 49, Rarity.MYTHIC, mage.cards.k.KarnLegacyReforged.class));
         cards.add(new SetCardInfo("Kiora, Sovereign of the Deep", 35, Rarity.MYTHIC, mage.cards.k.KioraSovereignOfTheDeep.class));
         cards.add(new SetCardInfo("Kolaghan Warmonger", 17, Rarity.UNCOMMON, mage.cards.k.KolaghanWarmonger.class));
         cards.add(new SetCardInfo("Markov Baron", 14, Rarity.UNCOMMON, mage.cards.m.MarkovBaron.class));