diff --git a/src/Builtin/BaseProcesses.cs b/src/Builtin/BaseProcesses.cs
index 4e4bb4c..ba689b1 100644
--- a/src/Builtin/BaseProcesses.cs
+++ b/src/Builtin/BaseProcesses.cs
@@ -30,6 +30,13 @@ namespace DCFApixels.DragonECS
     {
         void Run();
     }
+    [MetaName(nameof(RunFinally))]
+    [MetaColor(MetaColor.DragonRose)]
+    [MetaGroup(EcsConsts.PACK_GROUP, EcsConsts.PROCESSES_GROUP)]
+    public interface IEcsRunFinally : IEcsProcess
+    {
+        void RunFinally();
+    }
     [MetaName(nameof(Destroy))]
     [MetaColor(MetaColor.DragonRose)]
     [MetaGroup(EcsConsts.PACK_GROUP, EcsConsts.PROCESSES_GROUP)]
@@ -97,26 +104,45 @@ namespace DCFApixels.DragonECS.Internal
     [MetaID("2098527C9201F260C840BFD50BC7E0BA")]
     internal sealed class EcsRunRunner : EcsRunner<IEcsRun>, IEcsRun
     {
+        private readonly struct Pair
+        {
+            public readonly IEcsRun run;
+            public readonly IEcsRunFinally cleanup;
+            public Pair(IEcsRun run)
+            {
+                this.run = run;
+                cleanup = run as IEcsRunFinally;
+            }
+        }
+        private Pair[] _pairs;
 #if DEBUG && !DISABLE_DEBUG
         private EcsProfilerMarker[] _markers;
+#endif
         protected override void OnSetup()
         {
+            _pairs = new Pair[Process.Length];
+            for (int i = 0; i < Process.Length; i++)
+            {
+                _pairs[i] = new Pair(Process[i]);
+            }
+#if DEBUG && !DISABLE_DEBUG
             _markers = new EcsProfilerMarker[Process.Length];
             for (int i = 0; i < Process.Length; i++)
             {
                 _markers[i] = new EcsProfilerMarker($"{Process[i].GetMeta().Name}.{nameof(Run)}");
             }
-        }
 #endif
+        }
         public void Run()
         {
 #if DEBUG && !DISABLE_DEBUG
-            for (int i = 0, n = Process.Length < _markers.Length ? Process.Length : _markers.Length; i < n; i++)
+            for (int i = 0, n = _pairs.Length < _markers.Length ? _pairs.Length : _markers.Length; i < n; i++)
             {
+                var pair = _pairs[i];
                 _markers[i].Begin();
                 try
                 {
-                    Process[i].Run();
+                    pair.run.Run();
                 }
                 catch (Exception e)
                 {
@@ -125,6 +151,10 @@ namespace DCFApixels.DragonECS.Internal
 #endif
                     EcsDebug.PrintError(e);
                 }
+                finally
+                {
+                    pair.cleanup?.RunFinally();
+                }
                 _markers[i].End();
             }
 #else
diff --git a/src/EcsAspect.cs b/src/EcsAspect.cs
index 4bbfbed..145cfc8 100644
--- a/src/EcsAspect.cs
+++ b/src/EcsAspect.cs
@@ -25,7 +25,63 @@ namespace DCFApixels.DragonECS
 
         public static implicit operator Singleton<T>(SingletonMarker a) { return new Singleton<T>(a.Builder.World.ID); }
     }
-    public abstract class EcsAspect : ITemplateNode, IComponentMask
+    public interface IEcsAspect
+    {
+        EcsMask Mask { get; set; }
+    }
+
+    #region IEcsAspectExtensions tmp
+//    public static class IEcsAspectExtensions
+//    {
+//        public static void Apply(this IEcsAspect aspect, short worldID, int entityID)
+//        {
+//            EcsWorld world = EcsWorld.GetWorld(worldID);
+//            EcsMask mask = aspect.Mask;
+//            foreach (var incTypeID in mask._incs)
+//            {
+//                var pool = world.FindPoolInstance(incTypeID);
+//                if (pool != null)
+//                {
+//                    if (pool.Has(entityID) == false)
+//                    {
+//                        pool.AddEmpty(entityID);
+//                    }
+//                }
+//#if DEBUG
+//                else
+//                {
+//                    EcsDebug.PrintWarning("Component has not been added because the pool has not been initialized yet.");
+//                }
+//#endif
+//            }
+//            foreach (var excTypeID in mask._excs)
+//            {
+//                var pool = world.FindPoolInstance(excTypeID);
+//                if (pool != null && pool.Has(entityID))
+//                {
+//                    pool.Del(entityID);
+//                }
+//            }
+//        }
+//    }
+    #endregion
+
+    public static partial class API
+    {
+        public static IncludeMarker Inc
+        {
+            get { return EcsAspect.CurrentBuilder.Inc; }
+        }
+        public static ExcludeMarker Exc
+        {
+            get { return EcsAspect.CurrentBuilder.Exc; }
+        }
+        public static OptionalMarker Opt
+        {
+            get { return EcsAspect.CurrentBuilder.Opt; }
+        }
+    }
+    public abstract class EcsAspect : IEcsAspect, ITemplateNode, IComponentMask
     {
         #region Initialization Halpers
         [ThreadStatic]
@@ -43,7 +99,7 @@ namespace DCFApixels.DragonECS
                 return _constructorBuildersStack[_constructorBuildersStackIndex];
             }
         }
-        protected static Builder CurrentBuilder
+        public static Builder CurrentBuilder
         {
             get { return B; }
         }
@@ -77,6 +133,7 @@ namespace DCFApixels.DragonECS
         public EcsMask Mask
         {
             get { return _mask; }
+            set { }
         }
         public EcsWorld World
         {
@@ -138,7 +195,8 @@ namespace DCFApixels.DragonECS
 
             #region Constructors/New
             private Builder() { }
-            internal static unsafe TAspect New<TAspect>(EcsWorld world) where TAspect : EcsAspect, new()
+
+            internal static unsafe (TAspect aspect, EcsMask mask) New<TAspect>(EcsWorld world) where TAspect : new()
             {
                 //Get Builder
                 if (_constructorBuildersStack == null)
@@ -168,26 +226,34 @@ namespace DCFApixels.DragonECS
 
                 //Building
                 TAspect newAspect = new TAspect();
-                newAspect._source = world;
-                newAspect.Init(builder);
+                EcsAspect builtinAspect = newAspect as EcsAspect;
+                if(builtinAspect != null)
+                {
+                    builtinAspect._source = world;
+                    builtinAspect.Init(builder);
+                }
 
                 //Build Mask
                 if (staticMask == null)
                 {
                     staticMask = builder._maskBuilder.Build();
                     builder._maskBuilder = default;
-                    if (newAspect.IsStaticInitialization)
+                    if (builtinAspect == null || builtinAspect.IsStaticInitialization)
                     {
                         _staticMaskCache.Add(typeof(TAspect), staticMask);
                     }
                 }
-                newAspect._mask = staticMask.ToMask(world);
-                //var pools = new IEcsPool[builder._poolsBufferCount];
-                //Array.Copy(builder._poolsBuffer, pools, pools.Length);
-                newAspect._isBuilt = true;
+                EcsMask mask = staticMask.ToMask(world);
+                if(builtinAspect != null)
+                {
+                    builtinAspect._mask = mask;
+                    //var pools = new IEcsPool[builder._poolsBufferCount];
+                    //Array.Copy(builder._poolsBuffer, pools, pools.Length);
+                    builtinAspect._isBuilt = true;
+                }
 
                 _constructorBuildersStackIndex--;
-                return newAspect;
+                return (newAspect, mask);
             }
             #endregion
 
@@ -386,7 +452,9 @@ namespace DCFApixels.DragonECS
         }
     }
     #endregion
-
+}
+namespace DCFApixels.DragonECS.Core
+{
     #region Constraint Markers
     public readonly ref struct IncludeMarker
     {
diff --git a/src/EcsPipeline.Builder.cs b/src/EcsPipeline.Builder.cs
index 5f116d9..672b119 100644
--- a/src/EcsPipeline.Builder.cs
+++ b/src/EcsPipeline.Builder.cs
@@ -214,7 +214,7 @@ namespace DCFApixels.DragonECS
                 {
                     case IEcsProcess system: return AddSystem_Internal(system, settedAddParams);
                     case IEcsModule module: return AddModule_Internal(module, settedAddParams);
-                    default: Throw.ArgumentException("Unsupported type"); return this;
+                    default: Throw.ArgumentException($"{raw.GetMeta().TypeName} Unsupported type"); return this;
                 }
             }
             #endregion
diff --git a/src/EcsPipeline.cs b/src/EcsPipeline.cs
index 93460ad..89403df 100644
--- a/src/EcsPipeline.cs
+++ b/src/EcsPipeline.cs
@@ -68,7 +68,7 @@ namespace DCFApixels.DragonECS
         {
             get { return _isInit; }
         }
-        public bool IsDestoryed
+        public bool IsDestroyed
         {
             get { return _isDestoryed; }
         }
@@ -250,7 +250,7 @@ namespace DCFApixels.DragonECS
     {
         public static bool IsNullOrDestroyed(this EcsPipeline self)
         {
-            return self == null || self.IsDestoryed;
+            return self == null || self.IsDestroyed;
         }
         public static EcsPipeline.Builder Add(this EcsPipeline.Builder self, IEnumerable<IEcsProcess> range, string layerName = null)
         {
diff --git a/src/EcsRunner.cs b/src/EcsRunner.cs
index 4f6902e..7a30daa 100644
--- a/src/EcsRunner.cs
+++ b/src/EcsRunner.cs
@@ -4,6 +4,7 @@ using System;
 using System.Linq;
 using System.Runtime.CompilerServices;
 using static DCFApixels.DragonECS.EcsDebugUtility;
+#pragma warning disable CS0162 // Обнаружен недостижимый код
 
 namespace DCFApixels.DragonECS
 {
@@ -16,6 +17,7 @@ namespace DCFApixels.DragonECS
 
     namespace RunnersCore
     {
+        //добавить инъекцию в раннеры
         public abstract class EcsRunner
         {
             internal abstract void Init_Internal(EcsPipeline source);
@@ -57,6 +59,8 @@ namespace DCFApixels.DragonECS
 #endif
             }
             #endregion
+
+            public delegate void ActionWithData<in TProcess, T>(TProcess process, ref T Data);
         }
 
         [MetaColor(MetaColor.DragonRose)]
@@ -124,7 +128,12 @@ namespace DCFApixels.DragonECS
             #endregion
 
             #region RunHelper
-            public struct RunHelper
+#if DEBUG && !DISABLE_DEBUG
+            public
+#else
+            public readonly
+#endif
+                struct RunHelper
             {
                 private readonly EcsProcess<TProcess> _process;
 #if DEBUG && !DISABLE_DEBUG
@@ -182,7 +191,6 @@ namespace DCFApixels.DragonECS
                 #endregion
 
                 #region Do
-#pragma warning disable CS0162 // Обнаружен недостижимый код
                 [MethodImpl(MethodImplOptions.AggressiveInlining)]
                 public void Run(Action<TProcess> translationCallback)
                 {
@@ -223,7 +231,7 @@ namespace DCFApixels.DragonECS
                 }
 
                 [MethodImpl(MethodImplOptions.AggressiveInlining)]
-                public void Run<T0>(Action<TProcess, T0> translationCallback, T0 t0)
+                public void Run<TData>(ActionWithData<TProcess, TData> translationCallback, ref TData data)
                 {
 #if DEBUG && !DISABLE_DEBUG
                     CheckCache(translationCallback);
@@ -232,7 +240,7 @@ namespace DCFApixels.DragonECS
                         _markers[i].Begin();
                         try
                         {
-                            translationCallback(_process[i], t0);
+                            translationCallback(_process[i], ref data);
                         }
                         catch (Exception e)
                         {
@@ -248,7 +256,7 @@ namespace DCFApixels.DragonECS
                     {
                         try
                         {
-                            translationCallback(item, t0);
+                            translationCallback(item, ref data);
                         }
                         catch (Exception e)
                         {
@@ -260,128 +268,205 @@ namespace DCFApixels.DragonECS
                     }
 #endif
                 }
-
-                [MethodImpl(MethodImplOptions.AggressiveInlining)]
-                public void Run<T0, T1>(Action<TProcess, T0, T1> translationCallback, T0 t0, T1 t1)
-                {
-#if DEBUG && !DISABLE_DEBUG
-                    CheckCache(translationCallback);
-                    for (int i = 0, n = _process.Length < _markers.Length ? _process.Length : _markers.Length; i < n; i++)
-                    {
-                        _markers[i].Begin();
-                        try
-                        {
-                            translationCallback(_process[i], t0, t1);
-                        }
-                        catch (Exception e)
-                        {
-#if DISABLE_CATH_EXCEPTIONS
-                            throw;
-#endif
-                            EcsDebug.PrintError(e);
-                        }
-                        _markers[i].End();
-                    }
-#else
-                    foreach (var item in _process)
-                    {
-                        try
-                        {
-                            translationCallback(item, t0, t1);
-                        }
-                        catch (Exception e)
-                        {
-#if DISABLE_CATH_EXCEPTIONS
-                            throw;
-#endif
-                            EcsDebug.PrintError(e);
-                        }
-                    }
-#endif
-                }
-
-                [MethodImpl(MethodImplOptions.AggressiveInlining)]
-                public void Run<T0, T1, T2>(Action<TProcess, T0, T1, T2> translationCallback, T0 t0, T1 t1, T2 t2)
-                {
-#if DEBUG && !DISABLE_DEBUG
-                    CheckCache(translationCallback);
-                    for (int i = 0, n = _process.Length < _markers.Length ? _process.Length : _markers.Length; i < n; i++)
-                    {
-                        _markers[i].Begin();
-                        try
-                        {
-                            translationCallback(_process[i], t0, t1, t2);
-                        }
-                        catch (Exception e)
-                        {
-#if DISABLE_CATH_EXCEPTIONS
-                            throw;
-#endif
-                            EcsDebug.PrintError(e);
-                        }
-                        _markers[i].End();
-                    }
-#else
-                    foreach (var item in _process)
-                    {
-                        try
-                        {
-                            translationCallback(item, t0, t1, t2);
-                        }
-                        catch (Exception e)
-                        {
-#if DISABLE_CATH_EXCEPTIONS
-                            throw;
-#endif
-                            EcsDebug.PrintError(e);
-                        }
-                    }
-#endif
-                }
-
-                [MethodImpl(MethodImplOptions.AggressiveInlining)]
-                public void Run<T0, T1, T2, T3>(Action<TProcess, T0, T1, T2, T3> translationCallback, T0 t0, T1 t1, T2 t2, T3 t3)
-                {
-#if DEBUG && !DISABLE_DEBUG
-                    CheckCache(translationCallback);
-                    for (int i = 0, n = _process.Length < _markers.Length ? _process.Length : _markers.Length; i < n; i++)
-                    {
-                        _markers[i].Begin();
-                        try
-                        {
-                            translationCallback(_process[i], t0, t1, t2, t3);
-                        }
-                        catch (Exception e)
-                        {
-#if DISABLE_CATH_EXCEPTIONS
-                            throw;
-#endif
-                            EcsDebug.PrintError(e);
-                        }
-                        _markers[i].End();
-                    }
-#else
-                    foreach (var item in _process)
-                    {
-                        try
-                        {
-                            translationCallback(item, t0, t1, t2, t3);
-                        }
-                        catch (Exception e)
-                        {
-#if DISABLE_CATH_EXCEPTIONS
-                            throw;
-#endif
-                            EcsDebug.PrintError(e);
-                        }
-                    }
-#endif
-                }
-#pragma warning restore CS0162 // Обнаружен недостижимый код
-                //------------------------
                 #endregion
             }
             #endregion
+
+            #region RunHelperWithFinally
+#if DEBUG && !DISABLE_DEBUG
+            public
+#else
+            public readonly
+#endif
+                struct RunHelperWithFinally<TProcessFinally> where TProcessFinally : class, IEcsProcess
+            {
+                private readonly Pair[] _pairs;
+#if DEBUG && !DISABLE_DEBUG
+                private Delegate _cacheCheck;
+                private Delegate _cacheCheckF;
+                private bool _cacheCheckInit;
+                private readonly EcsProfilerMarker[] _markers;
+#endif
+
+                #region Constructors
+                public RunHelperWithFinally(EcsRunner<TProcess> runner) : this(runner,
+#if DEBUG && !DISABLE_DEBUG
+                    typeof(TProcess).ToMeta().Name)
+#else
+                    string.Empty)
+#endif
+                { }
+
+                public RunHelperWithFinally(EcsRunner<TProcess> runner, string methodName)
+                {
+                    _pairs = new Pair[runner.Process.Length];
+                    for (int i = 0; i < runner.Process.Length; i++)
+                    {
+                        _pairs[i] = new Pair(runner.Process[i]);
+                    }
+#if DEBUG && !DISABLE_DEBUG
+                    _cacheCheck = null;
+                    _cacheCheckF = null;
+                    _cacheCheckInit = false;
+                    _markers = new EcsProfilerMarker[_pairs.Length];
+                    for (int i = 0; i < _pairs.Length; i++)
+                    {
+                        _markers[i] = new EcsProfilerMarker($"{_pairs[i].run.GetMeta().Name}.{methodName}");
+                    }
+#endif
+                }
+                #endregion
+
+                #region Utils
+                private readonly struct Pair
+                {
+                    public readonly TProcess run;
+                    public readonly TProcessFinally runFinally;
+                    public Pair(TProcess run)
+                    {
+                        this.run = run;
+                        runFinally = run as TProcessFinally;
+                    }
+                }
+#if DEBUG && !DISABLE_DEBUG
+                [MethodImpl(MethodImplOptions.AggressiveInlining)]
+                private void CheckCache(Delegate d, Delegate df)
+                {
+                    if (_cacheCheckInit == false)
+                    {
+                        if (_cacheCheck == null)
+                        {
+                            _cacheCheck = d;
+                            _cacheCheckF = df;
+                        }
+                        else
+                        {
+                            if (ReferenceEquals(_cacheCheck, d) == false || ReferenceEquals(_cacheCheckF, df) == false)
+                            {
+                                EcsDebug.PrintWarning("The delegate is not cached");
+                            }
+                            _cacheCheckInit = true;
+                        }
+                    }
+                }
+#endif
+                #endregion
+
+                #region Do
+                [MethodImpl(MethodImplOptions.AggressiveInlining)]
+                public void Run(
+                    Action<TProcess> translationCallback,
+                    Action<TProcessFinally> translationFinnalyCallback)
+                {
+#if DEBUG && !DISABLE_DEBUG
+                    CheckCache(translationCallback, translationFinnalyCallback);
+                    for (int i = 0, n = _pairs.Length < _markers.Length ? _pairs.Length : _markers.Length; i < n; i++)
+                    {
+                        var pair = _pairs[i];
+                        _markers[i].Begin();
+                        try
+                        {
+                            translationCallback(pair.run);
+                        }
+                        catch (Exception e)
+                        {
+#if DISABLE_CATH_EXCEPTIONS
+                            throw;
+#endif
+                            EcsDebug.PrintError(e);
+                        }
+                        finally
+                        {
+                            if(pair.runFinally != null)
+                            {
+                                translationFinnalyCallback(pair.runFinally);
+                            }
+                        }
+                        _markers[i].End();
+                    }
+#else
+                    foreach (var item in _pairs)
+                    {
+                        try
+                        {
+                            translationCallback(item.run);
+                        }
+                        catch (Exception e)
+                        {
+#if DISABLE_CATH_EXCEPTIONS
+                            throw;
+#endif
+                            EcsDebug.PrintError(e);
+                        }
+                        finally
+                        {
+                            translationFinnalyCallback(item.runFinally);
+                        }
+                    }
+#endif
+                }
+
+                [MethodImpl(MethodImplOptions.AggressiveInlining)]
+                public void Run<TData>(
+                    ActionWithData<TProcess, TData> translationCallback,
+                    ActionWithData<TProcessFinally, TData> translationFinnalyCallback,
+                    ref TData data)
+                {
+#if DEBUG && !DISABLE_DEBUG
+                    CheckCache(translationCallback, translationFinnalyCallback);
+                    for (int i = 0, n = _pairs.Length < _markers.Length ? _pairs.Length : _markers.Length; i < n; i++)
+                    {
+                        var pair = _pairs[i];
+                        _markers[i].Begin();
+                        try
+                        {
+                            translationCallback(pair.run, ref data);
+                        }
+                        catch (Exception e)
+                        {
+#if DISABLE_CATH_EXCEPTIONS
+                            throw;
+#endif
+                            EcsDebug.PrintError(e);
+                        }
+                        finally
+                        {
+                            if (pair.runFinally != null)
+                            {
+                                translationFinnalyCallback(pair.runFinally, ref data);
+                            }
+                        }
+                        _markers[i].End();
+                    }
+#else
+                    foreach (var pair in _pairs)
+                    {
+                        try
+                        {
+                            translationCallback(pair.run, t0);
+                        }
+                        catch (Exception e)
+                        {
+#if DISABLE_CATH_EXCEPTIONS
+                            throw;
+#endif
+                            EcsDebug.PrintError(e);
+                        }
+                        finally
+                        {
+                            if (pair.runFinally != null)
+                            {
+                                translationFinnalyCallback(pair.runFinally, t0);
+                            }
+                        }
+                    }
+#endif
+                }
+                #endregion
+            }
+            #endregion
+
+            //----
         }
     }
 
diff --git a/src/EcsWorld.cache.cs b/src/EcsWorld.cache.cs
index 14fccb7..bcffb82 100644
--- a/src/EcsWorld.cache.cs
+++ b/src/EcsWorld.cache.cs
@@ -20,13 +20,22 @@ namespace DCFApixels.DragonECS
             }
         }
         internal readonly struct AspectCache<T> : IEcsWorldComponent<AspectCache<T>>
-            where T : EcsAspect, new()
+            where T : new()
         {
             public readonly T Instance;
-            public AspectCache(T instance) { Instance = instance; }
+            public readonly EcsMask Mask;
+            public AspectCache(T instance, EcsMask mask)
+            {
+                Instance = instance;
+                Mask = mask;
+            }
             void IEcsWorldComponent<AspectCache<T>>.Init(ref AspectCache<T> component, EcsWorld world)
             {
-                component = new AspectCache<T>(EcsAspect.Builder.New<T>(world));
+#if DEBUG
+                AllowedInWorldsAttribute.CheckAllows<T>(world);
+#endif
+                var result = EcsAspect.Builder.New<T>(world);
+                component = new AspectCache<T>(result.aspect, result.mask);
             }
             void IEcsWorldComponent<AspectCache<T>>.OnDestroy(ref AspectCache<T> component, EcsWorld world)
             {
@@ -36,7 +45,7 @@ namespace DCFApixels.DragonECS
 
         internal readonly struct WhereQueryCache<TExecutor, TAspcet> : IEcsWorldComponent<WhereQueryCache<TExecutor, TAspcet>>
             where TExecutor : MaskQueryExecutor, new()
-            where TAspcet : EcsAspect, new()
+            where TAspcet : new()
         {
             public readonly TExecutor Executor;
             public readonly TAspcet Aspcet;
@@ -47,9 +56,9 @@ namespace DCFApixels.DragonECS
             }
             void IEcsWorldComponent<WhereQueryCache<TExecutor, TAspcet>>.Init(ref WhereQueryCache<TExecutor, TAspcet> component, EcsWorld world)
             {
-                TAspcet aspect = world.GetAspect<TAspcet>();
-                TExecutor instance = world.GetExecutorForMask<TExecutor>(aspect.Mask);
-                instance.Initialize(world, aspect.Mask);
+                TAspcet aspect = world.GetAspect<TAspcet>(out EcsMask mask);
+                TExecutor instance = world.GetExecutorForMask<TExecutor>(mask);
+                instance.Initialize(world, mask);
                 component = new WhereQueryCache<TExecutor, TAspcet>(instance, aspect);
             }
             void IEcsWorldComponent<WhereQueryCache<TExecutor, TAspcet>>.OnDestroy(ref WhereQueryCache<TExecutor, TAspcet> component, EcsWorld world)
diff --git a/src/EcsWorld.cs b/src/EcsWorld.cs
index e2d6bd1..3c36bf6 100644
--- a/src/EcsWorld.cs
+++ b/src/EcsWorld.cs
@@ -250,14 +250,21 @@ namespace DCFApixels.DragonECS
         [UnityEngine.Scripting.Preserve]
 #endif
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
-        public TAspect GetAspect<TAspect>() where TAspect : EcsAspect, new()
+        public TAspect GetAspect<TAspect>() where TAspect : new()
         {
             return Get<AspectCache<TAspect>>().Instance;
         }
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public TAspect GetAspect<TAspect>(out EcsMask mask) where TAspect : new()
+        {
+            var result = Get<AspectCache<TAspect>>();
+            mask = result.Mask;
+            return result.Instance;
+        }
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public void GetQueryCache<TExecutor, TAspect>(out TExecutor executor, out TAspect aspect)
             where TExecutor : MaskQueryExecutor, new()
-            where TAspect : EcsAspect, new()
+            where TAspect : new()
         {
             ref var cmp = ref Get<WhereQueryCache<TExecutor, TAspect>>();
             executor = cmp.Executor;
@@ -270,6 +277,11 @@ namespace DCFApixels.DragonECS
             return ref WorldComponentPool<T>.GetForWorld(ID);
         }
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public bool Has<T>() where T : struct
+        {
+            return WorldComponentPool<T>.Has(ID);
+        }
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public ref T GetUnchecked<T>() where T : struct
         {
             return ref WorldComponentPool<T>.GetForWorldUnchecked(ID);
@@ -280,6 +292,11 @@ namespace DCFApixels.DragonECS
             return ref WorldComponentPool<T>.GetForWorld(worldID);
         }
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static bool Has<T>(short worldID) where T : struct
+        {
+            return WorldComponentPool<T>.Has(worldID);
+        }
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static ref T GetUnchecked<T>(short worldID) where T : struct
         {
             return ref WorldComponentPool<T>.GetForWorldUnchecked(worldID);
@@ -874,6 +891,8 @@ namespace DCFApixels.DragonECS
         #region Debug Components
         [ThreadStatic]
         private static int[] _componentIDsBuffer;
+        [ThreadStatic]
+        private static object[] _componentsBuffer;
         public ReadOnlySpan<int> GetComponentTypeIDsFor(int entityID)
         {
             int count = GetComponentTypeIDsFor_Internal(entityID, ref _componentIDsBuffer);
@@ -920,6 +939,19 @@ namespace DCFApixels.DragonECS
                 }
             }
         }
+        public ReadOnlySpan<object> GetComponentsFor(int entityID)
+        {
+            int count = GetComponentTypeIDsFor_Internal(entityID, ref _componentIDsBuffer);
+            if (_componentsBuffer == null || _componentsBuffer.Length < count)
+            {
+                _componentsBuffer = new object[count];
+            }
+            for (int i = 0; i < count; i++)
+            {
+                _componentsBuffer[i] = _pools[_componentIDsBuffer[i]].GetRaw(entityID);
+            }
+            return new ReadOnlySpan<object>(_componentsBuffer, 0, count);
+        }
         public void GetComponentsFor(int entityID, List<object> list)
         {
             list.Clear();
diff --git a/src/EcsWorld.static.cs b/src/EcsWorld.static.cs
index 38dffa5..d364a2f 100644
--- a/src/EcsWorld.static.cs
+++ b/src/EcsWorld.static.cs
@@ -169,6 +169,10 @@ namespace DCFApixels.DragonECS
                                 Array.Resize(ref _items, _items.Length << 1);
                             }
 
+#if DEBUG
+                            AllowedInWorldsAttribute.CheckAllows<T>(_worlds[worldID]);
+#endif
+
                             _interface.Init(ref _items[itemIndex], _worlds[worldID]);
 
                             var world = GetWorld(worldID);
diff --git a/src/Executors/Queries.cs b/src/Executors/Queries.cs
index 214b658..171386f 100644
--- a/src/Executors/Queries.cs
+++ b/src/Executors/Queries.cs
@@ -13,7 +13,7 @@ namespace DCFApixels.DragonECS
     {
         #region Where
         public static EcsSpan Where<TCollection, TAspect>(this TCollection entities, out TAspect aspect)
-            where TAspect : EcsAspect, new()
+            where TAspect : new()
             where TCollection : IEntityStorage
         {
             if (ReferenceEquals(entities, entities.World))
@@ -24,12 +24,12 @@ namespace DCFApixels.DragonECS
             return entities.ToSpan().Where(out aspect);
         }
         public static EcsSpan Where<TAspect>(this EcsReadonlyGroup group, out TAspect aspect)
-            where TAspect : EcsAspect, new()
+            where TAspect : new()
         {
             return group.ToSpan().Where(out aspect);
         }
         public static EcsSpan Where<TAspect>(this EcsSpan span, out TAspect aspect)
-            where TAspect : EcsAspect, new()
+            where TAspect : new()
         {
             span.World.GetQueryCache(out EcsWhereExecutor executor, out aspect);
             return executor.ExecuteFor(span);
@@ -58,7 +58,7 @@ namespace DCFApixels.DragonECS
 
         #region Where with sort
         public static EcsSpan Where<TCollection, TAspect>(this TCollection entities, out TAspect aspect, Comparison<int> comparison)
-            where TAspect : EcsAspect, new()
+            where TAspect : new()
             where TCollection : IEntityStorage
         {
             if (ReferenceEquals(entities, entities.World))
@@ -69,12 +69,12 @@ namespace DCFApixels.DragonECS
             return entities.ToSpan().Where(out aspect, comparison);
         }
         public static EcsSpan Where<TAspect>(this EcsReadonlyGroup group, out TAspect aspect, Comparison<int> comparison)
-            where TAspect : EcsAspect, new()
+            where TAspect : new()
         {
             return group.ToSpan().Where(out aspect, comparison);
         }
         public static EcsSpan Where<TAspect>(this EcsSpan span, out TAspect aspect, Comparison<int> comparison)
-            where TAspect : EcsAspect, new()
+            where TAspect : new()
         {
             span.World.GetQueryCache(out EcsWhereExecutor executor, out aspect);
             return executor.ExecuteFor(span, comparison);
@@ -103,7 +103,7 @@ namespace DCFApixels.DragonECS
 
         #region WhereToGroup
         public static EcsReadonlyGroup WhereToGroup<TCollection, TAspect>(this TCollection entities, out TAspect aspect)
-            where TAspect : EcsAspect, new()
+            where TAspect : new()
             where TCollection : IEntityStorage
         {
             if (ReferenceEquals(entities, entities.World))
@@ -114,12 +114,12 @@ namespace DCFApixels.DragonECS
             return entities.ToSpan().WhereToGroup(out aspect);
         }
         public static EcsReadonlyGroup WhereToGroup<TAspect>(this EcsReadonlyGroup group, out TAspect aspect)
-            where TAspect : EcsAspect, new()
+            where TAspect : new()
         {
             return group.ToSpan().WhereToGroup(out aspect);
         }
         public static EcsReadonlyGroup WhereToGroup<TAspect>(this EcsSpan span, out TAspect aspect)
-            where TAspect : EcsAspect, new()
+            where TAspect : new()
         {
             span.World.GetQueryCache(out EcsWhereToGroupExecutor executor, out aspect);
             return executor.ExecuteFor(span);
diff --git a/src/Utils/AllowedInWorldsAttribute.cs b/src/Utils/AllowedInWorldsAttribute.cs
new file mode 100644
index 0000000..038cda3
--- /dev/null
+++ b/src/Utils/AllowedInWorldsAttribute.cs
@@ -0,0 +1,43 @@
+using DCFApixels.DragonECS.Internal;
+using System;
+
+namespace DCFApixels.DragonECS
+{
+    [AttributeUsage(AttributeTargets.Struct | AttributeTargets.Class, Inherited = false, AllowMultiple = true)]
+    public sealed class AllowedInWorldsAttribute : Attribute
+    {
+        public object[] AllowedWorlds;
+        public AllowedInWorldsAttribute(params object[] allowedWorlds)
+        {
+            AllowedWorlds = allowedWorlds;
+        }
+
+
+        public static void CheckAllows<T>(EcsWorld world)
+        {
+            Type componentType = typeof(T);
+            Type worldType = world.GetType();
+            if (componentType.TryGetAttribute(out AllowedInWorldsAttribute attribute))
+            {
+                foreach (var worldTag in attribute.AllowedWorlds)
+                {
+                    bool result = false;
+                    if (worldTag is Type worldTypeTag)
+                    {
+                        result = worldTypeTag == worldType;
+                    }
+                    else
+                    {
+                        string worldStringTag = worldTag.ToString();
+                        result = world.Name == worldStringTag;
+                    }
+                    if (result)
+                    {
+                        return;
+                    }
+                }
+                throw new EcsFrameworkException($"Using component {componentType.ToMeta().TypeName} is not allowed in the {worldType.ToMeta().TypeName} world.");
+            }
+        }
+    }
+}
diff --git a/src/Utils/AllowedInWorldsAttribute.cs.meta b/src/Utils/AllowedInWorldsAttribute.cs.meta
new file mode 100644
index 0000000..2888e88
--- /dev/null
+++ b/src/Utils/AllowedInWorldsAttribute.cs.meta
@@ -0,0 +1,11 @@
+fileFormatVersion: 2
+guid: a39694cb8b5876346968ef45a8272000
+MonoImporter:
+  externalObjects: {}
+  serializedVersion: 2
+  defaultReferences: []
+  executionOrder: 0
+  icon: {instanceID: 0}
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