cannot get XP from the same character in PVP more than once per reboot

src/engine/objects/PlayerCharacter.java

@@ -181,6 +181,8 @@ public class PlayerCharacter extends AbstractCharacter {
     public boolean depositingWarehouse = false;
     public Building warehouseBuilding;
 
+    public ArrayList<PlayerCharacter> killedCharacters = new ArrayList<>();
+
     /**
      * No Id Constructor
      */