* Some minor reworks to prevent exceptions.

Mage.Sets/src/mage/cards/c/ConundrumSphinx.java

@@ -25,11 +25,11 @@
  *  authors and should not be interpreted as representing official policies, either expressed
  *  or implied, of BetaSteward_at_googlemail.com.
  */
-
 package mage.cards.c;
 
 import java.util.UUID;
 import mage.MageInt;
+import mage.MageObject;
 import mage.abilities.Ability;
 import mage.abilities.common.AttacksTriggeredAbility;
 import mage.abilities.effects.OneShotEffect;
@@ -40,6 +40,7 @@ import mage.choices.Choice;
 import mage.choices.ChoiceImpl;
 import mage.constants.CardType;
 import mage.constants.Outcome;
+import mage.constants.SubType;
 import mage.constants.Zone;
 import mage.game.Game;
 import mage.players.Player;
@@ -52,12 +53,16 @@ public class ConundrumSphinx extends CardImpl {
 
     public ConundrumSphinx(UUID ownerId, CardSetInfo setInfo) {
         super(ownerId, setInfo, new CardType[]{CardType.CREATURE}, "{2}{U}{U}");
-        this.subtype.add("Sphinx");
+        this.subtype.add(SubType.SPHINX);
 
         this.power = new MageInt(4);
         this.toughness = new MageInt(4);
 
+        //Flying
         this.addAbility(FlyingAbility.getInstance());
+        // Whenever Conundrum Sphinx attacks, each player names a card. Then each player reveals the top card of his or her library.
+        // If the card a player revealed is the card he or she named, that player puts it into his or her hand.
+        // If it's not, that player puts it on the bottom of his or her library.
         this.addAbility(new AttacksTriggeredAbility(new ConundrumSphinxEffect(), false));
     }
 
@@ -85,32 +90,41 @@ class ConundrumSphinxEffect extends OneShotEffect {
 
     @Override
     public boolean apply(Game game, Ability source) {
+        MageObject sourceObject = source.getSourceObject(game);
+        Player controller = game.getPlayer(source.getControllerId());
+        if (controller != null && sourceObject != null) {
             Choice cardChoice = new ChoiceImpl();
             cardChoice.setChoices(CardRepository.instance.getNames());
-        for (Player player: game.getPlayers().values()) {
+            Players:
+            for (UUID playerId : game.getState().getPlayersInRange(controller.getId(), game)) {
+                Player player = game.getPlayer(playerId);
+                if (player != null) {
                     if (player.getLibrary().hasCards()) {
                         cardChoice.clearChoice();
                         while (!player.choose(Outcome.DrawCard, cardChoice, game) && player.canRespond()) {
                             if (!player.canRespond()) {
-                        return false;
+                                continue Players;
                             }
                         }
                         String cardName = cardChoice.getChoice();
-                game.informPlayers("Conundrum Sphinx, player: " + player.getLogName() + ", named card: [" + cardName + ']');
+                        game.informPlayers(sourceObject.getLogName() + ", player: " + player.getLogName() + ", named: [" + cardName + ']');
                         Card card = player.getLibrary().removeFromTop(game);
-                Cards cards  = new CardsImpl();
-                cards.add(card);
-                player.revealCards("Conundrum Sphinx", cards, game);
+                        if (card != null) {
+                            Cards cards = new CardsImpl(card);
+                            player.revealCards(sourceObject.getIdName(), cards, game);
                             if (card.getName().equals(cardName)) {
-                    card.moveToZone(Zone.HAND, source.getSourceId(), game, true);
+                                player.moveCards(cards, Zone.HAND, source, game);
+                            } else {
+                                player.putCardsOnBottomOfLibrary(cards, game, source, false);
+                            }
                         }
-                else {
-                    card.moveToZone(Zone.LIBRARY, source.getSourceId(), game, false);
                     }
                 }
             }
             return true;
         }
+        return false;
+    }
 
     @Override
     public ConundrumSphinxEffect copy() {

Mage.Sets/src/mage/cards/f/Fireball.java

@@ -57,7 +57,7 @@ public class Fireball extends CardImpl {
 
     @Override
     public void adjustCosts(Ability ability, Game game) {
-        int numTargets = ability.getTargets().get(0).getTargets().size();
+        int numTargets = ability.getTargets().isEmpty() ? 0 : ability.getTargets().get(0).getTargets().size();
         if (numTargets > 1) {
             ability.getManaCostsToPay().add(new GenericManaCost(numTargets - 1));
         }

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

@@ -4,6 +4,7 @@
  */
 package mage.abilities.effects.common;
 
+import java.util.Objects;
 import mage.MageObject;
 import mage.abilities.Ability;
 import mage.abilities.DelayedTriggeredAbility;
@@ -19,8 +20,6 @@ import mage.game.stack.Spell;
 import mage.game.stack.StackObject;
 import mage.players.Player;
 
-import java.util.Objects;
-
 /**
  *
  * @author jeffwadsworth
@@ -53,6 +52,9 @@ public class EpicEffect extends OneShotEffect {
         if (controller != null) {
             StackObject stackObject = game.getStack().getStackObject(source.getId());
             Spell spell = (Spell) stackObject;
+            if (spell == null) {
+                return false;
+            }
             spell = spell.copySpell(source.getControllerId());
             // Remove Epic effect from the spell
             Effect epicEffect = null;