[DRC] Implement Priest of the Crossing (#13394)

* Implement Priest of the Crossing

* Add common dynamic value for "creatures that died under your control this turn"

Mage/src/main/java/mage/abilities/dynamicvalue/common/CreaturesYouControlDiedCount.java

@@ -0,0 +1,33 @@
+package mage.abilities.dynamicvalue.common;
+
+import mage.abilities.Ability;
+import mage.abilities.dynamicvalue.DynamicValue;
+import mage.abilities.effects.Effect;
+import mage.game.Game;
+import mage.watchers.common.CreaturesDiedWatcher;
+
+public enum CreaturesYouControlDiedCount implements DynamicValue {
+    instance;
+
+    @Override
+    public int calculate(Game game, Ability sourceAbility, Effect effect) {
+        return game.getState()
+                .getWatcher(CreaturesDiedWatcher.class)
+                .getAmountOfCreaturesDiedThisTurnByController(sourceAbility.getControllerId());
+    }
+
+    @Override
+    public CreaturesYouControlDiedCount copy() {
+        return this;
+    }
+
+    @Override
+    public String getMessage() {
+        return "creature that died under your control this turn";
+    }
+
+    @Override
+    public String toString() {
+        return "1";
+    }
+}