diff --git a/Assets/Battle/BattleController.cs b/Assets/Battle/BattleController.cs
index ec3a997..13ab0c6 100644
--- a/Assets/Battle/BattleController.cs
+++ b/Assets/Battle/BattleController.cs
@@ -217,6 +217,9 @@ public class BattleController : MonoBehaviour, IBattleEffectApplier, IBattleEffe
         } else {
             this.heroDeck.MoveCardToDiscard(card);
         }
+
+        yield return new WaitForSeconds(0.5f);
+        CheckState();
     }
 
     public IEnumerator UseMonsterCard(MonsterCard card) {
@@ -230,6 +233,7 @@ public class BattleController : MonoBehaviour, IBattleEffectApplier, IBattleEffe
         }
 
         yield return new WaitForSeconds(0.5f);
+        CheckState();
     }
 
     public void NotifyHeroTurnPassed() {
@@ -267,7 +271,22 @@ public class BattleController : MonoBehaviour, IBattleEffectApplier, IBattleEffe
         // Cleanup expired triggers
         this.damageTriggers.RemoveAll(t => t.Expired);
     }
-    
+
+    private void CheckState() {
+        foreach (BattleParticipant p in this.heroes) {
+            p.CheckState();
+        }
+        foreach (BattleParticipant p in this.monsters) {
+            p.CheckState();
+        }
+        if (System.Array.TrueForAll(this.heroes, h => !h.IsAlive())) {
+            Debug.Log("You lost!");
+        }
+        if (System.Array.TrueForAll(this.monsters, m => !m.IsAlive())) {
+            Debug.Log("You won!");
+        }
+    }
+
     public EnergyPool HeroEnergy {get => this.heroEnergy;}
     public EnergyPool MonsterEnergy {get => this.monsterEnergy;}
 
@@ -282,10 +301,12 @@ public class BattleController : MonoBehaviour, IBattleEffectApplier, IBattleEffe
     }
 
     public void IncreaseMaxHP(IncreaseMaxHPEffect effect) {
+        if (effect.Target == null) return;
         effect.Target.IncreaseMaxHP(effect.Amount);
     }
 
     public void AcquireHeroCards(AcquireCardsEffect effect) {
+        if (effect.Participant == null) return;
         BattleHero hero = (BattleHero) effect.Participant;
         foreach (CardId cardId in effect.CardIds) {
             HeroCard acquiredCard = this.heroCardDatabase.CreateCard((int) cardId, hero);
@@ -307,6 +328,8 @@ public class BattleController : MonoBehaviour, IBattleEffectApplier, IBattleEffe
     private List<DamageTrigger> damageTriggers = new List<DamageTrigger>();
 
     public int DealDamage(DealDamageEffect effect) {
+        if (effect.Target == null) return 0;
+
         int damageDealt = effect.Target.DealDamage(effect.Amount);
         foreach (DamageTrigger dt in this.damageTriggers) {
             if (dt.IsTriggeredBy(effect)) {
@@ -321,11 +344,14 @@ public class BattleController : MonoBehaviour, IBattleEffectApplier, IBattleEffe
     }
 
     public int Heal(HealEffect effect) {
+        if (effect.Target == null) return 0;
+
         int healedAmount = effect.Target.Heal(effect.Amount);
         return healedAmount;
     }
 
     public void AddBlock(BlockEffect effect) {
+        if (effect.Target == null) return;
         effect.Target.AddBlock(effect.Amount);
     }
 
diff --git a/Assets/Battle/BattleParticipant.cs b/Assets/Battle/BattleParticipant.cs
index c296f9f..42ed922 100644
--- a/Assets/Battle/BattleParticipant.cs
+++ b/Assets/Battle/BattleParticipant.cs
@@ -47,11 +47,14 @@ public class BattleParticipant
         }
         damage = Math.Min(this.hp, damage);
         this.hp -= damage;
+        return damage;
+    }
+
+    public void CheckState() {
         if (this.hp <= 0) {
             this.dead = true;
             TriggerOnDeath();
         }
-        return damage;
     }
 
     public int Heal(int amount) {
diff --git a/Assets/Battle/BattleScene.unity b/Assets/Battle/BattleScene.unity
index c08edc6..33a8689 100644
--- a/Assets/Battle/BattleScene.unity
+++ b/Assets/Battle/BattleScene.unity
@@ -306,8 +306,8 @@ MonoBehaviour:
   heroIds: 010000000000000002000000
   monsterIds: 000000000100000000000000
   cardIds: 00000000000000000000000000000000010000000100000001000000030000000300000004000000
-  mCardIds: 00000000000000000000000000000000000000000000000000000000000000000000000000000000
-  mCardOwnerIndexes: 00000000000000000000000000000000000000000200000002000000020000000200000002000000
+  mCardIds: 01000000010000000100000001000000000000000000000000000000000000000200000002000000
+  mCardOwnerIndexes: 01000000010000000100000001000000000000000000000000000000020000000200000002000000
   heroUIPrefab: {fileID: 6641511084601005557, guid: ef1b469b45cedee418e4c4adf577cd00,
     type: 3}
   uiCanvas: {fileID: 35522588}
diff --git a/Assets/Battle/CardsMonsters/QuickSwiftDeathMCard.cs b/Assets/Battle/CardsMonsters/QuickSwiftDeathMCard.cs
new file mode 100644
index 0000000..258bd5b
--- /dev/null
+++ b/Assets/Battle/CardsMonsters/QuickSwiftDeathMCard.cs
@@ -0,0 +1,18 @@
+using System.Collections;
+using System.Collections.Generic;
+using UnityEngine;
+
+public class QuickSwiftDeathMCard : MonsterCard
+{
+    public QuickSwiftDeathMCard(BattleParticipant owner)
+        : base(owner, MCardId.GolemFist, "Quick Swift Death", 0, CardType.Attack,
+            "Deals 100 damage to target. Target: nearest hero.") {
+    }
+
+    public override IEnumerator Use(IBattleEffectApplier effectApplier, MonsterViewpoint monsterViewpoint) {
+        BattleParticipant target = AIUtils.GetNearestHero(monsterViewpoint, this.owner);
+        DealDamageEffect damageEffect = new DealDamageEffect(target, 100);
+        effectApplier.Apply(damageEffect);
+        yield break;
+    }
+}
diff --git a/Assets/Battle/CardsMonsters/QuickSwiftDeathMCard.cs.meta b/Assets/Battle/CardsMonsters/QuickSwiftDeathMCard.cs.meta
new file mode 100644
index 0000000..096a17b
--- /dev/null
+++ b/Assets/Battle/CardsMonsters/QuickSwiftDeathMCard.cs.meta
@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: cc74c54a87a767f47bd838afb171504e
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 
diff --git a/Assets/Battle/MonsterAI/AIUtils.cs b/Assets/Battle/MonsterAI/AIUtils.cs
index a65b005..fba5687 100644
--- a/Assets/Battle/MonsterAI/AIUtils.cs
+++ b/Assets/Battle/MonsterAI/AIUtils.cs
@@ -17,6 +17,7 @@ public class AIUtils {
                 nearestDistance = distance;
             }
         }
+        if (nearestHeroIndex == -1) return null;
         return monsterViewpoint.Heroes[nearestHeroIndex];
     }
 
@@ -38,6 +39,7 @@ public class AIUtils {
                 highestHP = heroHP;
             }
         }
+        if (highestHPHeroIndex == -1) return null;
         return monsterViewpoint.Heroes[highestHPHeroIndex];
     }
 }
diff --git a/Assets/Battle/MonsterCardDatabase.cs b/Assets/Battle/MonsterCardDatabase.cs
index 046f7cf..76780d7 100644
--- a/Assets/Battle/MonsterCardDatabase.cs
+++ b/Assets/Battle/MonsterCardDatabase.cs
@@ -5,6 +5,7 @@ using UnityEngine;
 public enum MCardId {
     VampireFangs,
     GolemFist,
+    QuickSwiftDeath,
 }
 
 public class MonsterCardDatabase : CardDatabase<MonsterCard>
@@ -17,6 +18,8 @@ public class MonsterCardDatabase : CardDatabase<MonsterCard>
                 return new VampireFangsMCard(owner);
             case MCardId.GolemFist:
                 return new GolemFistMCard(owner);
+            case MCardId.QuickSwiftDeath:
+                return new QuickSwiftDeathMCard(owner);
             default:
                 throw new System.ArgumentException("MCardId unknown", "id");
         }
diff --git a/TODO.txt b/TODO.txt
index f30f8a5..761b38b 100644
--- a/TODO.txt
+++ b/TODO.txt
@@ -1,3 +1,2 @@
-- Make battle end as state based effect
-- Check death as state based effect
-- Rename CardId to HCardId
\ No newline at end of file
+- Rename CardId to HCardId
+- Animate rearrange hand after card is used
\ No newline at end of file