[minor] Fixed rule text generation.

Mage.Sets/src/mage/sets/newphyrexia/MyrSuperion.java

@@ -28,10 +28,12 @@
 package mage.sets.newphyrexia;
 
 import java.util.UUID;
+import mage.MageInt;
+import mage.abilities.StaticAbility;
+import mage.cards.CardImpl;
 import mage.constants.CardType;
 import mage.constants.Rarity;
-import mage.MageInt;
-import mage.cards.CardImpl;
+import mage.constants.Zone;
 import mage.filter.common.FilterCreaturePermanent;
 
 /**
@@ -51,6 +53,7 @@ public class MyrSuperion extends CardImpl<MyrSuperion> {
         this.toughness = new MageInt(6);
 
         // Spend only mana produced by creatures to cast Myr Superion.
+        this.addAbility(new MyrSuperionStaticAbility());
         this.getSpellAbility().getManaCostsToPay().setSourceFilter(filter);
         this.getSpellAbility().getManaCosts().setSourceFilter(filter);
     }
@@ -64,3 +67,25 @@ public class MyrSuperion extends CardImpl<MyrSuperion> {
         return new MyrSuperion(this);
     }
 }
+
+class MyrSuperionStaticAbility extends StaticAbility<MyrSuperionStaticAbility> {
+
+    public MyrSuperionStaticAbility() {
+        super(Zone.STACK, null);
+    }
+
+    public MyrSuperionStaticAbility(MyrSuperionStaticAbility ability) {
+        super(ability);
+    }
+
+    @Override
+    public MyrSuperionStaticAbility copy() {
+        return new MyrSuperionStaticAbility(this);
+    }
+
+    @Override
+    public String getRule() {
+        return "Spend only mana produced by creatures to cast {this}.";
+    }
+
+}

Mage/src/mage/abilities/Modes.java

@@ -33,7 +33,6 @@ import java.util.Map;
 import java.util.Set;
 import java.util.UUID;
 import mage.abilities.costs.OptionalAdditionalModeSourceCosts;
-import mage.abilities.costs.OptionalAdditionalSourceCosts;
 import mage.cards.Card;
 import mage.game.Game;
 import mage.players.Player;
@@ -175,6 +174,7 @@ public class Modes extends LinkedHashMap<UUID, Mode> {
         }
         if (this.size() > 1) {
             sb.delete(sb.length() - andOr.length(), sb.length());
+            sb.append(".");
         }
         return sb.toString();
     }