diff --git a/Mage.Sets/src/mage/cards/e/ErisRoarOfTheStorm.java b/Mage.Sets/src/mage/cards/e/ErisRoarOfTheStorm.java
new file mode 100644
index 00000000000..1f9e8631eb1
--- /dev/null
+++ b/Mage.Sets/src/mage/cards/e/ErisRoarOfTheStorm.java
@@ -0,0 +1,134 @@
+package mage.cards.e;
+
+import mage.MageInt;
+import mage.MageObject;
+import mage.abilities.Ability;
+import mage.abilities.common.CastSecondSpellTriggeredAbility;
+import mage.abilities.common.SimpleStaticAbility;
+import mage.abilities.dynamicvalue.DynamicValue;
+import mage.abilities.effects.Effect;
+import mage.abilities.effects.common.CreateTokenEffect;
+import mage.abilities.effects.common.cost.SpellCostReductionForEachSourceEffect;
+import mage.abilities.hint.Hint;
+import mage.abilities.keyword.FlyingAbility;
+import mage.abilities.keyword.ProwessAbility;
+import mage.cards.CardImpl;
+import mage.cards.CardSetInfo;
+import mage.constants.CardType;
+import mage.constants.SubType;
+import mage.constants.SuperType;
+import mage.constants.Zone;
+import mage.filter.StaticFilters;
+import mage.game.Game;
+import mage.game.permanent.token.DragonElementalToken;
+import mage.players.Player;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Optional;
+import java.util.UUID;
+import java.util.stream.Collectors;
+import java.util.stream.Stream;
+
+/**
+ * @author TheElk801
+ */
+public final class ErisRoarOfTheStorm extends CardImpl {
+
+    public ErisRoarOfTheStorm(UUID ownerId, CardSetInfo setInfo) {
+        super(ownerId, setInfo, new CardType[]{CardType.CREATURE}, "{8}{U}{R}");
+
+        this.supertype.add(SuperType.LEGENDARY);
+        this.subtype.add(SubType.ELEMENTAL);
+        this.subtype.add(SubType.WARLOCK);
+        this.power = new MageInt(4);
+        this.toughness = new MageInt(4);
+
+        // This spell costs {2} less to cast for each different mana value among instant and sorcery cards in your graveyard.
+        this.addAbility(new SimpleStaticAbility(
+                Zone.ALL,
+                new SpellCostReductionForEachSourceEffect(
+                        2, ErisRoarOfTheStormValue.instance
+                ).setCanWorksOnStackOnly(true)
+        ).setRuleAtTheTop(true).addHint(ErisRoarOfTheStormHint.instance));
+
+        // Flying
+        this.addAbility(FlyingAbility.getInstance());
+
+        // Prowess
+        this.addAbility(new ProwessAbility());
+
+        // Whenever you cast your second spell each turn, create a 4/4 red Dragon Elemental creature token with flying and prowess.
+        this.addAbility(new CastSecondSpellTriggeredAbility(new CreateTokenEffect(new DragonElementalToken())));
+    }
+
+    private ErisRoarOfTheStorm(final ErisRoarOfTheStorm card) {
+        super(card);
+    }
+
+    @Override
+    public ErisRoarOfTheStorm copy() {
+        return new ErisRoarOfTheStorm(this);
+    }
+}
+
+enum ErisRoarOfTheStormValue implements DynamicValue {
+    instance;
+
+    @Override
+    public int calculate(Game game, Ability sourceAbility, Effect effect) {
+        return makeStream(game, sourceAbility)
+                .mapToInt(x -> 1)
+                .sum();
+    }
+
+    static Stream<Integer> makeStream(Game game, Ability source) {
+        return Optional
+                .ofNullable(game.getPlayer(source.getControllerId()))
+                .map(Player::getGraveyard)
+                .map(g -> g.getCards(StaticFilters.FILTER_CARD_INSTANT_OR_SORCERY, game))
+                .map(Collection::stream)
+                .map(s -> s.map(MageObject::getManaValue))
+                .map(Stream::distinct)
+                .orElseGet(Stream::empty);
+    }
+
+    @Override
+    public ErisRoarOfTheStormValue copy() {
+        return this;
+    }
+
+    @Override
+    public String getMessage() {
+        return "different mana value among instant and sorcery cards in your graveyard";
+    }
+
+    @Override
+    public String toString() {
+        return "1";
+    }
+}
+
+enum ErisRoarOfTheStormHint implements Hint {
+    instance;
+
+    @Override
+    public String getText(Game game, Ability ability) {
+        Player player = game.getPlayer(ability.getControllerId());
+        if (player == null) {
+            return null;
+        }
+        List<String> values = ErisRoarOfTheStormValue
+                .makeStream(game, ability)
+                .sorted()
+                .map(String::valueOf)
+                .collect(Collectors.toList());
+        return "Different mana values among instants and sorceries in your graveyard: " + values.size()
+                + (values.size() > 0 ? " (" + String.join(", ", values) + ')' : "");
+    }
+
+    @Override
+    public Hint copy() {
+        return this;
+    }
+}
diff --git a/Mage.Sets/src/mage/sets/OutlawsOfThunderJunctionCommander.java b/Mage.Sets/src/mage/sets/OutlawsOfThunderJunctionCommander.java
index 2b5a748315c..51add649756 100644
--- a/Mage.Sets/src/mage/sets/OutlawsOfThunderJunctionCommander.java
+++ b/Mage.Sets/src/mage/sets/OutlawsOfThunderJunctionCommander.java
@@ -24,6 +24,7 @@ public final class OutlawsOfThunderJunctionCommander extends ExpansionSet {
         cards.add(new SetCardInfo("Back in Town", 18, Rarity.RARE, mage.cards.b.BackInTown.class));
         cards.add(new SetCardInfo("Charred Graverobber", 19, Rarity.RARE, mage.cards.c.CharredGraverobber.class));
         cards.add(new SetCardInfo("Elemental Eruption", 27, Rarity.RARE, mage.cards.e.ElementalEruption.class));
+        cards.add(new SetCardInfo("Eris, Roar of the Storm", 5, Rarity.MYTHIC, mage.cards.e.ErisRoarOfTheStorm.class));
         cards.add(new SetCardInfo("Kirri, Talented Sprout", 43, Rarity.MYTHIC, mage.cards.k.KirriTalentedSprout.class));
         cards.add(new SetCardInfo("Leyline Dowser", 39, Rarity.RARE, mage.cards.l.LeylineDowser.class));
         cards.add(new SetCardInfo("Stella Lee, Wild Card", 3, Rarity.MYTHIC, mage.cards.s.StellaLeeWildCard.class));