diff --git a/Mage.Sets/src/mage/cards/b/BorosChallenger.java b/Mage.Sets/src/mage/cards/b/BorosChallenger.java
new file mode 100644
index 00000000000..b05423b33fd
--- /dev/null
+++ b/Mage.Sets/src/mage/cards/b/BorosChallenger.java
@@ -0,0 +1,49 @@
+package mage.cards.b;
+
+import java.util.UUID;
+import mage.MageInt;
+import mage.abilities.common.SimpleActivatedAbility;
+import mage.abilities.costs.mana.ManaCostsImpl;
+import mage.abilities.effects.common.continuous.BoostSourceEffect;
+import mage.constants.SubType;
+import mage.abilities.keyword.MentorAbility;
+import mage.cards.CardImpl;
+import mage.cards.CardSetInfo;
+import mage.constants.CardType;
+import mage.constants.Duration;
+import mage.constants.Zone;
+
+/**
+ *
+ * @author TheElk801
+ */
+public final class BorosChallenger extends CardImpl {
+
+    public BorosChallenger(UUID ownerId, CardSetInfo setInfo) {
+        super(ownerId, setInfo, new CardType[]{CardType.CREATURE}, "{R}{W}");
+
+        this.subtype.add(SubType.HUMAN);
+        this.subtype.add(SubType.SOLDIER);
+        this.power = new MageInt(2);
+        this.toughness = new MageInt(3);
+
+        // Mentor
+        this.addAbility(new MentorAbility());
+
+        // {2}{R}{W}: Boros Challenger gets +1/+1 until end of turn.
+        this.addAbility(new SimpleActivatedAbility(
+                Zone.BATTLEFIELD,
+                new BoostSourceEffect(1, 1, Duration.EndOfTurn),
+                new ManaCostsImpl("{2}{R}{W}")
+        ));
+    }
+
+    public BorosChallenger(final BorosChallenger card) {
+        super(card);
+    }
+
+    @Override
+    public BorosChallenger copy() {
+        return new BorosChallenger(this);
+    }
+}
diff --git a/Mage.Sets/src/mage/sets/GuildsOfRavnica.java b/Mage.Sets/src/mage/sets/GuildsOfRavnica.java
index 8b5d5bda115..b8fb13f75ff 100644
--- a/Mage.Sets/src/mage/sets/GuildsOfRavnica.java
+++ b/Mage.Sets/src/mage/sets/GuildsOfRavnica.java
@@ -22,6 +22,7 @@ public final class GuildsOfRavnica extends ExpansionSet {
         this.numBoosterRare = 1;
         this.ratioBoosterMythic = 8;
 
+        cards.add(new SetCardInfo("Boros Challenger", 156, Rarity.UNCOMMON, mage.cards.b.BorosChallenger.class));
         cards.add(new SetCardInfo("Emmara, Soul of the Accord", 168, Rarity.RARE, mage.cards.e.EmmaraSoulOfTheAccord.class));
         cards.add(new SetCardInfo("Impervious Greatwurm", 273, Rarity.MYTHIC, mage.cards.i.ImperviousGreatwurm.class));
         cards.add(new SetCardInfo("Narcomoeba", 47, Rarity.RARE, mage.cards.n.Narcomoeba.class));
diff --git a/Mage/src/main/java/mage/abilities/keyword/MentorAbility.java b/Mage/src/main/java/mage/abilities/keyword/MentorAbility.java
new file mode 100644
index 00000000000..bd579657dac
--- /dev/null
+++ b/Mage/src/main/java/mage/abilities/keyword/MentorAbility.java
@@ -0,0 +1,56 @@
+package mage.abilities.keyword;
+
+import mage.abilities.common.AttacksTriggeredAbility;
+import mage.abilities.effects.common.counter.AddCountersTargetEffect;
+import mage.cards.Card;
+import mage.counters.CounterType;
+import mage.filter.common.FilterCreaturePermanent;
+import mage.filter.predicate.ObjectSourcePlayer;
+import mage.filter.predicate.ObjectSourcePlayerPredicate;
+import mage.filter.predicate.permanent.AttackingPredicate;
+import mage.game.Game;
+import mage.game.permanent.Permanent;
+import mage.target.common.TargetCreaturePermanent;
+
+/**
+ *
+ * @author TheElk801
+ */
+public class MentorAbility extends AttacksTriggeredAbility {
+
+    private static final FilterCreaturePermanent filter = new FilterCreaturePermanent("attacking creature with lesser power");
+
+    static {
+        filter.add(new AttackingPredicate());
+        filter.add(new MentorAbilityPredicate());
+    }
+
+    public MentorAbility() {
+        super(new AddCountersTargetEffect(CounterType.P1P1.createInstance()), false);
+        this.addTarget(new TargetCreaturePermanent(filter));
+    }
+
+    public MentorAbility(final MentorAbility ability) {
+        super(ability);
+    }
+
+    @Override
+    public String getRule() {
+        return "mentor <i>(Whenever this creature attacks, put a +1/+1 counter on target attacking creature with lesser power.)</i>";
+    }
+
+    @Override
+    public MentorAbility copy() {
+        return new MentorAbility(this);
+    }
+
+}
+
+class MentorAbilityPredicate implements ObjectSourcePlayerPredicate<ObjectSourcePlayer<Card>> {
+
+    @Override
+    public boolean apply(ObjectSourcePlayer<Card> input, Game game) {
+        Permanent sourcePermanent = game.getPermanentOrLKIBattlefield(input.getSourceId());
+        return sourcePermanent != null && input.getObject().getPower().getValue() < sourcePermanent.getPower().getValue();
+    }
+}