Modifications to LandfallAbility:

Bloodghast's landfall comes only when he's in the yard, added constructor for such a case where the zone may not be battlefield.
Modifications to Condition:
     Javadoc'ed the apply method.
Renamed ConditionalEffect to be ConditionalContinousEffect

Mage/src/mage/abilities/common/LandfallAbility.java

@@ -48,6 +48,10 @@ public class LandfallAbility extends TriggeredAbilityImpl<LandfallAbility> {
 		super(Zone.BATTLEFIELD, effect, optional);
 	}
 
+	public LandfallAbility ( Zone zone, Effect effect, Boolean optional ) {
+		super(zone, effect, optional);
+	}
+
 	public LandfallAbility(final LandfallAbility ability) {
 		super(ability);
 	}

Mage/src/mage/abilities/condition/Condition.java

@@ -11,5 +11,12 @@ import java.io.Serializable;
  * @author nantuko
  */
 public interface Condition extends Serializable {
+	/**
+	 * Checks the game to see if this condition applies for the given ability.
+	 * 
+	 * @param game
+	 * @param source
+	 * @return
+	 */
     boolean apply(Game game, Ability source);
 }

Mage/src/mage/abilities/condition/common/Controls.java

@@ -0,0 +1,107 @@
+/*
+ *  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.abilities.condition.common;
+
+import mage.abilities.Ability;
+import mage.abilities.condition.Condition;
+import mage.filter.FilterPermanent;
+import mage.game.Game;
+
+/**
+ * Battlefield checking condition.  This condition can decorate other conditions
+ * as well as be used standalone.
+ *
+ * @see #Controls(mage.filter.Filter)
+ * @see #Controls(mage.filter.Filter, mage.abilities.condition.Condition)
+ * 
+ * @author matthew.maurer
+ */
+public class Controls implements Condition {
+
+	public static enum CountType { MORE_THAN, FEWER_THAN, EQUAL_TO };
+	private FilterPermanent filter;
+	private Condition condition;
+	private CountType type;
+	private int count;
+
+	/**
+	 * Applies a filter, a {@link CountType}, and count to permanents on the
+	 * battlefield when checking the condition during the
+	 * {@link #apply(mage.game.Game, mage.abilities.Ability) apply} method invocation.
+	 * 
+	 * @param filter
+	 */
+	public Controls ( FilterPermanent filter, CountType type, int count ) {
+		this.filter = filter;
+		this.type = type;
+		this.count = count;
+	}
+
+	/**
+	 * Applies a filter, a {@link CountType}, and count to permanents on the
+	 * battlefield and calls the decorated condition to see if it
+	 * {@link #apply(mage.game.Game, mage.abilities.Ability) applies}
+	 * as well.  This will force both conditions to apply for this to be true.
+	 * 
+	 * @param filter
+	 * @param conditionToDecorate
+	 */
+	public Controls ( FilterPermanent filter, CountType type, int count, Condition conditionToDecorate ) {
+		this(filter, type, count);
+		this.condition = conditionToDecorate;
+	}
+
+	/*
+	 * {@inheritDoc}
+	 */
+	@Override
+	public boolean apply(Game game, Ability source) {
+		boolean conditionApplies = false;
+
+		switch ( this.type ) {
+			case FEWER_THAN:
+				conditionApplies = game.getBattlefield().countAll(filter, source.getControllerId()) > this.count;
+				break;
+			case MORE_THAN:
+				conditionApplies = game.getBattlefield().countAll(filter, source.getControllerId()) < this.count;
+				break;
+			case EQUAL_TO:
+				conditionApplies = game.getBattlefield().countAll(filter, source.getControllerId()) == this.count;
+				break;
+		}
+
+		//If a decorated condition exists, check it as well and apply them together.
+		if ( this.condition != null ) {
+			conditionApplies = conditionApplies && this.condition.apply(game, source);
+		}
+
+		return conditionApplies;
+	}
+
+}

Mage/src/mage/abilities/decorator/ConditionalContinousEffect.java

@@ -8,17 +8,17 @@ import mage.abilities.effects.ContinuousEffectImpl;
 import mage.game.Game;
 
 /**
- * Adds condition to effect. Acts as decorator.
+ * Adds condition to {@link ContinuousEffect}. Acts as decorator.
  *
  * @author nantuko
  */
-public class ConditionalEffect extends ContinuousEffectImpl<ConditionalEffect> {
+public class ConditionalContinousEffect extends ContinuousEffectImpl<ConditionalContinousEffect> {
 
     protected ContinuousEffect effect;
     protected Condition condition;
     protected String text;
 
-    public ConditionalEffect(ContinuousEffect effect, Condition condition, String text) {
+    public ConditionalContinousEffect(ContinuousEffect effect, Condition condition, String text) {
         super(effect.getDuration(), effect.getLayer(), effect.getSublayer(), effect.getOutcome());
         this.effect = effect;
         this.condition = condition;
@@ -47,8 +47,8 @@ public class ConditionalEffect extends ContinuousEffectImpl<ConditionalEffect> {
     }
 
     @Override
-    public ConditionalEffect copy() {
+    public ConditionalContinousEffect copy() {
-        return new ConditionalEffect(effect, condition, text);
+        return new ConditionalContinousEffect(effect, condition, text);
     }
 
     @Override

Mage/src/mage/abilities/decorator/ConditionalOneShotEffect.java

@@ -0,0 +1,75 @@
+/*
+ *  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.abilities.decorator;
+
+import mage.abilities.Ability;
+import mage.abilities.condition.Condition;
+import mage.abilities.effects.OneShotEffect;
+import mage.game.Game;
+
+/**
+ * Adds condition to {@link OneShotEffect}. Acts as decorator.
+ * 
+ * @author maurer.it_at_gmail.com
+ */
+public class ConditionalOneShotEffect extends OneShotEffect<ConditionalOneShotEffect> {
+
+	private OneShotEffect effect;
+	private Condition condition;
+	private String text;
+
+	public ConditionalOneShotEffect ( OneShotEffect effect, Condition condition, String text ) {
+		super(effect.getOutcome());
+		this.effect = effect;
+		this.condition = condition;
+		this.text = text;
+	}
+
+	public ConditionalOneShotEffect ( ConditionalOneShotEffect effect ) {
+		this(effect, effect.condition, effect.text);
+	}
+
+	@Override
+	public boolean apply ( Game game, Ability source ) {
+		if ( condition.apply(game, source) ) {
+			return effect.apply(game, source);
+		}
+		return false;
+	}
+
+	@Override
+	public ConditionalOneShotEffect copy ( ) {
+		return new ConditionalOneShotEffect ( this );
+	}
+
+	@Override
+	public String getText(Ability source) {
+		return this.text;
+	}
+}