diff --git a/DragonECS.csproj b/DragonECS.csproj
index 1d093cd..4f2db5b 100644
--- a/DragonECS.csproj
+++ b/DragonECS.csproj
@@ -10,7 +10,7 @@
         <RootNamespace>DCFApixels.DragonECS</RootNamespace>
 
         <Title>DragonECS</Title>
-        <Version>0.8.60</Version>
+        <Version>0.8.61</Version>
         <Authors>DCFApixels</Authors>
         <Description>ECS Framework for Game Engines with C# and .Net Platform</Description>
         <Copyright>DCFApixels</Copyright>
diff --git a/package.json b/package.json
index 59a5d8a..1051df6 100644
--- a/package.json
+++ b/package.json
@@ -8,7 +8,7 @@
     "displayName": "DragonECS",
     "description": "C# Entity Component System Framework",
     "unity": "2020.3",
-    "version": "0.8.60",
+    "version": "0.8.61",
     "repository": {
         "type": "git",
         "url": "https://github.com/DCFApixels/DragonECS.git"
diff --git a/src/Builtin/Aspects.cs b/src/Builtin/Aspects.cs
index 708d64d..d8197ab 100644
--- a/src/Builtin/Aspects.cs
+++ b/src/Builtin/Aspects.cs
@@ -6,14 +6,14 @@ namespace DCFApixels.DragonECS
 
     public sealed class SingleAspect<TPool> : EcsAspect where TPool : IEcsPoolImplementation, new()
     {
-        public readonly TPool pool = CurrentBuilder.IncludePool<TPool>();
+        public readonly TPool pool = B.IncludePool<TPool>();
     }
     public sealed class CombinedAspect<A0, A1> : EcsAspect
         where A0 : EcsAspect, new()
         where A1 : EcsAspect, new()
     {
-        public readonly A0 a0 = CurrentBuilder.Combine<A0>();
-        public readonly A1 a1 = CurrentBuilder.Combine<A1>();
+        public readonly A0 a0 = B.Combine<A0>();
+        public readonly A1 a1 = B.Combine<A1>();
         public void Deconstruct(out A0 a0, out A1 a1)
         {
             a0 = this.a0;
@@ -26,9 +26,9 @@ namespace DCFApixels.DragonECS
         where A1 : EcsAspect, new()
         where A2 : EcsAspect, new()
     {
-        public readonly A0 a0 = CurrentBuilder.Combine<A0>();
-        public readonly A1 a1 = CurrentBuilder.Combine<A1>();
-        public readonly A2 a2 = CurrentBuilder.Combine<A2>();
+        public readonly A0 a0 = B.Combine<A0>();
+        public readonly A1 a1 = B.Combine<A1>();
+        public readonly A2 a2 = B.Combine<A2>();
         public void Deconstruct(out A0 a0, out A1 a1, out A2 a2)
         {
             a0 = this.a0;
@@ -43,10 +43,10 @@ namespace DCFApixels.DragonECS
         where A2 : EcsAspect, new()
         where A3 : EcsAspect, new()
     {
-        public readonly A0 a0 = CurrentBuilder.Combine<A0>();
-        public readonly A1 a1 = CurrentBuilder.Combine<A1>();
-        public readonly A2 a2 = CurrentBuilder.Combine<A2>();
-        public readonly A3 a3 = CurrentBuilder.Combine<A3>();
+        public readonly A0 a0 = B.Combine<A0>();
+        public readonly A1 a1 = B.Combine<A1>();
+        public readonly A2 a2 = B.Combine<A2>();
+        public readonly A3 a3 = B.Combine<A3>();
         public void Deconstruct(out A0 a0, out A1 a1, out A2 a2, out A3 a3)
         {
             a0 = this.a0;
@@ -63,11 +63,11 @@ namespace DCFApixels.DragonECS
         where A3 : EcsAspect, new()
         where A4 : EcsAspect, new()
     {
-        public readonly A0 a0 = CurrentBuilder.Combine<A0>();
-        public readonly A1 a1 = CurrentBuilder.Combine<A1>();
-        public readonly A2 a2 = CurrentBuilder.Combine<A2>();
-        public readonly A3 a3 = CurrentBuilder.Combine<A3>();
-        public readonly A4 a4 = CurrentBuilder.Combine<A4>();
+        public readonly A0 a0 = B.Combine<A0>();
+        public readonly A1 a1 = B.Combine<A1>();
+        public readonly A2 a2 = B.Combine<A2>();
+        public readonly A3 a3 = B.Combine<A3>();
+        public readonly A4 a4 = B.Combine<A4>();
         public void Deconstruct(out A0 a0, out A1 a1, out A2 a2, out A3 a3, out A4 a4)
         {
             a0 = this.a0;
@@ -86,12 +86,12 @@ namespace DCFApixels.DragonECS
         where A4 : EcsAspect, new()
         where A5 : EcsAspect, new()
     {
-        public readonly A0 a0 = CurrentBuilder.Combine<A0>();
-        public readonly A1 a1 = CurrentBuilder.Combine<A1>();
-        public readonly A2 a2 = CurrentBuilder.Combine<A2>();
-        public readonly A3 a3 = CurrentBuilder.Combine<A3>();
-        public readonly A4 a4 = CurrentBuilder.Combine<A4>();
-        public readonly A5 a5 = CurrentBuilder.Combine<A5>();
+        public readonly A0 a0 = B.Combine<A0>();
+        public readonly A1 a1 = B.Combine<A1>();
+        public readonly A2 a2 = B.Combine<A2>();
+        public readonly A3 a3 = B.Combine<A3>();
+        public readonly A4 a4 = B.Combine<A4>();
+        public readonly A5 a5 = B.Combine<A5>();
         public void Deconstruct(out A0 a0, out A1 a1, out A2 a2, out A3 a3, out A4 a4, out A5 a5)
         {
             a0 = this.a0;
diff --git a/src/EcsAspect.cs b/src/EcsAspect.cs
index 98b7dfe..d025f82 100644
--- a/src/EcsAspect.cs
+++ b/src/EcsAspect.cs
@@ -6,6 +6,25 @@ using System.Collections.Generic;
 
 namespace DCFApixels.DragonECS
 {
+    public readonly struct Singleton<T> where T : struct
+    {
+        public readonly short WorldID;
+        public Singleton(short worldID)
+        {
+            WorldID = worldID;
+            EcsWorld.GetData<T>(worldID);
+        }
+        public EcsWorld World
+        {
+            get { return EcsWorld.GetWorld(WorldID); }
+        }
+        public ref T Value
+        {
+            get { return ref EcsWorld.GetDataUnchecked<T>(WorldID); }
+        }
+
+        public static implicit operator Singleton<T>(SingletonMarker a) { return new Singleton<T>(a.Builder.World.ID); }
+    }
     public abstract class EcsAspect : ITemplateNode, IComponentMask
     {
         #region Initialization Halpers
@@ -13,7 +32,7 @@ namespace DCFApixels.DragonECS
         private static Builder[] _constructorBuildersStack;
         [ThreadStatic]
         private static int _constructorBuildersStackIndex;
-        protected static Builder CurrentBuilder
+        protected static Builder B
         {
             get
             {
@@ -24,17 +43,25 @@ namespace DCFApixels.DragonECS
                 return _constructorBuildersStack[_constructorBuildersStackIndex];
             }
         }
+        protected static Builder CurrentBuilder
+        {
+            get { return B; }
+        }
         protected static IncludeMarker Inc
         {
-            get { return CurrentBuilder.Inc; }
+            get { return B.Inc; }
         }
         protected static ExcludeMarker Exc
         {
-            get { return CurrentBuilder.Exc; }
+            get { return B.Exc; }
         }
         protected static OptionalMarker Opt
         {
-            get { return CurrentBuilder.Opt; }
+            get { return B.Opt; }
+        }
+        protected static SingletonMarker Singleton
+        {
+            get { return B.Singleton; }
         }
         #endregion
 
@@ -102,6 +129,10 @@ namespace DCFApixels.DragonECS
             {
                 get { return new OptionalMarker(this); }
             }
+            public SingletonMarker Singleton
+            {
+                get { return new SingletonMarker(this); }
+            }
             public EcsWorld World
             {
                 get { return _world; }
@@ -164,6 +195,10 @@ namespace DCFApixels.DragonECS
             #endregion
 
             #region Include/Exclude/Optional/Combine/Except
+            public Singleton<T> Get<T>() where T : struct
+            {
+                return new Singleton<T>(_world.ID);
+            }
             public TPool IncludePool<TPool>() where TPool : IEcsPoolImplementation, new()
             {
                 var pool = CachePool<TPool>();
@@ -265,7 +300,7 @@ namespace DCFApixels.DragonECS
                 {
                     if (pool.Has(entityID) == false)
                     {
-                        pool.AddRaw(entityID, null);
+                        pool.AddEmpty(entityID);
                     }
                 }
 #if DEBUG
@@ -397,5 +432,17 @@ namespace DCFApixels.DragonECS
             return _builder.OptionalPool<T>();
         }
     }
+    public readonly ref struct SingletonMarker
+    {
+        public readonly EcsAspect.Builder Builder;
+        public SingletonMarker(EcsAspect.Builder builder)
+        {
+            Builder = builder;
+        }
+        public T Get<T>() where T : struct
+        {
+            return Builder.World.Get<T>();
+        }
+    }
     #endregion
 }
\ No newline at end of file
diff --git a/src/Pools/EcsPool.cs b/src/Pools/EcsPool.cs
index c8d8045..c3f624b 100644
--- a/src/Pools/EcsPool.cs
+++ b/src/Pools/EcsPool.cs
@@ -259,6 +259,7 @@ namespace DCFApixels.DragonECS
         #endregion
 
         #region Other
+        void IEcsPool.AddEmpty(int entityID) { Add(entityID); }
         void IEcsPool.AddRaw(int entityID, object dataRaw)
         {
             Add(entityID) = dataRaw == null ? default : (T)dataRaw;
diff --git a/src/Pools/EcsPoolBase.cs b/src/Pools/EcsPoolBase.cs
index 6f6f713..3bed942 100644
--- a/src/Pools/EcsPoolBase.cs
+++ b/src/Pools/EcsPoolBase.cs
@@ -88,6 +88,12 @@ namespace DCFApixels.DragonECS.Internal
         {
 #if (DEBUG && !DISABLE_DEBUG)
             throw new NullInstanceException();
+#endif
+        }
+        void IEcsPool.AddEmpty(int entityID)
+        {
+#if (DEBUG && !DISABLE_DEBUG)
+            throw new NullInstanceException();
 #endif
         }
         void IEcsPool.AddRaw(int entityID, object dataRaw)
@@ -101,7 +107,7 @@ namespace DCFApixels.DragonECS.Internal
 #if (DEBUG && !DISABLE_DEBUG)
             throw new NullInstanceException();
 #else
-                return null;
+            return null;
 #endif
         }
         void IEcsPool.SetRaw(int entity, object dataRaw)
@@ -179,6 +185,7 @@ namespace DCFApixels.DragonECS
     public interface IEcsPool : IEcsReadonlyPool
     {
         #region Methods
+        void AddEmpty(int entityID);
         void AddRaw(int entityID, object dataRaw);
         void SetRaw(int entityID, object dataRaw);
         void Del(int entityID);
diff --git a/src/Pools/EcsTagPool.cs b/src/Pools/EcsTagPool.cs
index 893bacb..0fe8260 100644
--- a/src/Pools/EcsTagPool.cs
+++ b/src/Pools/EcsTagPool.cs
@@ -224,6 +224,7 @@ namespace DCFApixels.DragonECS
         #endregion
 
         #region Other
+        void IEcsPool.AddEmpty(int entityID) { Add(entityID); }
         void IEcsPool.AddRaw(int entityID, object dataRaw) { Add(entityID); }
         object IEcsReadonlyPool.GetRaw(int entityID)
         {