Added Phyrexian Dreadnought.

Mage.Server/src/main/java/mage/server/ChatManager.java

@@ -62,7 +62,9 @@ public class ChatManager {
     }
 
     public void leaveChat(UUID chatId, UUID userId) {
-        chatSessions.get(chatId).kill(userId, User.DisconnectReason.CleaningUp);
+        if (chatSessions.containsKey(chatId)) {
+            chatSessions.get(chatId).kill(userId, User.DisconnectReason.CleaningUp);
+        }
     }
 
     public void destroyChatSession(UUID chatId) {

Mage.Sets/src/mage/sets/championsofkamigawa/NezumiGraverobber.java

@@ -71,6 +71,7 @@ public class NezumiGraverobber extends CardImpl<NezumiGraverobber> {
         this.flipCard = true;
         this.flipCardName = "Nighteyes The Desecrator";
 
+        // {1}{B}: Exile target card from an opponent's graveyard. If no cards are in that graveyard, flip Nezumi Graverobber.
         Ability ability = new SimpleActivatedAbility(Zone.BATTLEFIELD, new ExileTargetEffect(), new ManaCostsImpl("{1}{B}"));
         ability.addTarget(new TargetCardInOpponentsGraveyard(new FilterCard("card from an opponent's graveyard")));
         ability.addEffect(new NezumiGraverobberFlipEffect());
@@ -127,7 +128,7 @@ class NezumiGraverobberFlipEffect extends OneShotEffect<NezumiGraverobberFlipEff
 
 class NighteyesTheDesecratorToken extends Token {
     NighteyesTheDesecratorToken() {
-        super("Nighteyes The Desecrator", "");
+            super("Nighteyes The Desecrator", "");
         supertype.add("Legendary");
         cardType.add(CardType.CREATURE);
         color.setBlack(true);
@@ -135,6 +136,7 @@ class NighteyesTheDesecratorToken extends Token {
         subtype.add("Wizard");
         power = new MageInt(4);
         toughness = new MageInt(2);
+        // {4}{B}: Put target creature card from a graveyard onto the battlefield under your control.
         Ability ability = new SimpleActivatedAbility(Zone.BATTLEFIELD, new ReturnFromGraveyardToBattlefieldTargetEffect(), new ManaCostsImpl("{4}{B}"));
         ability.addTarget(new TargetCardInGraveyard(new FilterCreatureCard("creature card from a graveyard")));
         this.addAbility(ability);

Mage.Sets/src/mage/sets/mirage/PhyrexianDreadnought.java

@@ -0,0 +1,129 @@
+/*
+ *  Copyright 2010 BetaSteward_at_googlemail.com. All rights reserved.
+ *
+ *  Redistribution and use in source and binary forms, with or without modification, are
+ *  permitted provided that the following conditions are met:
+ *
+ *     1. Redistributions of source code must retain the above copyright notice, this list of
+ *        conditions and the following disclaimer.
+ *
+ *     2. Redistributions in binary form must reproduce the above copyright notice, this list
+ *        of conditions and the following disclaimer in the documentation and/or other materials
+ *        provided with the distribution.
+ *
+ *  THIS SOFTWARE IS PROVIDED BY BetaSteward_at_googlemail.com ``AS IS'' AND ANY EXPRESS OR IMPLIED
+ *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
+ *  FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL BetaSteward_at_googlemail.com OR
+ *  CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ *  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ *  ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
+ *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ *  ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ *  The views and conclusions contained in the software and documentation are those of the
+ *  authors and should not be interpreted as representing official policies, either expressed
+ *  or implied, of BetaSteward_at_googlemail.com.
+ */
+package mage.sets.mirage;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+import mage.MageInt;
+import mage.abilities.Ability;
+import mage.abilities.common.EntersBattlefieldTriggeredAbility;
+import mage.abilities.costs.CostImpl;
+import mage.abilities.effects.common.SacrificeSourceUnlessPaysEffect;
+import mage.abilities.keyword.TrampleAbility;
+import mage.cards.CardImpl;
+import mage.constants.CardType;
+import mage.constants.Outcome;
+import mage.constants.Rarity;
+import mage.filter.common.FilterControlledCreaturePermanent;
+import mage.filter.common.FilterCreaturePermanent;
+import mage.filter.predicate.permanent.AnotherPredicate;
+import mage.game.Game;
+import mage.game.permanent.Permanent;
+import mage.target.common.TargetControlledCreaturePermanent;
+
+/**
+ *
+ * @author LevelX2
+ */
+public class PhyrexianDreadnought extends CardImpl<PhyrexianDreadnought> {
+
+    public PhyrexianDreadnought(UUID ownerId) {
+        super(ownerId, 280, "Phyrexian Dreadnought", Rarity.RARE, new CardType[]{CardType.ARTIFACT, CardType.CREATURE}, "{1}");
+        this.expansionSetCode = "MIR";
+        this.subtype.add("Dreadnought");
+
+        this.power = new MageInt(12);
+        this.toughness = new MageInt(12);
+
+        // Trample
+        this.addAbility(TrampleAbility.getInstance());
+        // When Phyrexian Dreadnought enters the battlefield, sacrifice it unless you sacrifice any number of creatures with total power 12 or greater.
+        this.addAbility(new EntersBattlefieldTriggeredAbility(new SacrificeSourceUnlessPaysEffect(new PhyrexianDreadnoughtSacrificeCost())));
+
+    }
+
+    public PhyrexianDreadnought(final PhyrexianDreadnought card) {
+        super(card);
+    }
+
+    @Override
+    public PhyrexianDreadnought copy() {
+        return new PhyrexianDreadnought(this);
+    }
+}
+
+class PhyrexianDreadnoughtSacrificeCost extends CostImpl<PhyrexianDreadnoughtSacrificeCost> {
+
+    private static final FilterControlledCreaturePermanent filter = new FilterControlledCreaturePermanent("any number of creatures with total power 12 or greater");
+
+    static {
+        filter.add(new AnotherPredicate());
+    }
+
+    public PhyrexianDreadnoughtSacrificeCost() {
+        this.addTarget(new TargetControlledCreaturePermanent(0, Integer.MAX_VALUE, filter, true, false));
+        this.text = "sacrifice any number of creatures with total power 12 or greater";
+    }
+
+    public PhyrexianDreadnoughtSacrificeCost(final PhyrexianDreadnoughtSacrificeCost cost) {
+        super(cost);
+    }
+
+    @Override
+    public boolean pay(Ability ability, Game game, UUID sourceId, UUID controllerId, boolean noMana) {
+        int sumPower = 0;
+        if (targets.choose(Outcome.Sacrifice, controllerId, sourceId, game)) {
+            for (UUID targetId: targets.get(0).getTargets()) {
+                Permanent permanent = game.getPermanent(targetId);
+                if (permanent != null && permanent.sacrifice(sourceId, game)) {
+                    sumPower += permanent.getPower().getValue();
+                }
+            }
+        }
+        game.informPlayers(new StringBuilder("Sacrificed creatures with total power of ").append(sumPower).toString());
+        paid = sumPower >= 12;
+        return paid;
+    }
+
+    @Override
+    public boolean canPay(UUID sourceId, UUID controllerId, Game game) {
+        int sumPower = 0;
+        for (Permanent permanent :game.getBattlefield().getAllActivePermanents(new FilterCreaturePermanent(), controllerId, game)) {
+            if (!permanent.getId().equals(sourceId)) {
+                sumPower += permanent.getPower().getValue();
+            }
+        }
+        return sumPower >= 12;
+    }
+
+    @Override
+    public PhyrexianDreadnoughtSacrificeCost copy() {
+        return new PhyrexianDreadnoughtSacrificeCost(this);
+    }
+}