diff --git a/Engine.Core/CoroutineManager.cs b/Engine.Core/CoroutineManager.cs
index 511f755..8ec9e22 100644
--- a/Engine.Core/CoroutineManager.cs
+++ b/Engine.Core/CoroutineManager.cs
@@ -3,7 +3,7 @@ using System.Collections.Generic;
 
 namespace Syntriax.Engine.Core;
 
-public class CoroutineManager : UniverseObject
+public class CoroutineManager : Behaviour
 {
     private readonly List<IEnumerator> enumerators = [];
 
@@ -18,12 +18,12 @@ public class CoroutineManager : UniverseObject
         enumerators.Remove(enumerator);
     }
 
-    protected override void OnEnteringUniverse(IUniverse universe)
+    protected override void OnEnteredUniverse(IUniverse universe)
     {
         universe.OnUpdate.AddListener(OnUpdate);
     }
 
-    protected override void OnExitingUniverse(IUniverse universe)
+    protected override void OnExitedUniverse(IUniverse universe)
     {
         universe.OnUpdate.RemoveListener(OnUpdate);
     }
diff --git a/Engine.Core/Systems/DrawManager.cs b/Engine.Core/Systems/DrawManager.cs
index 64c320a..cd7fef0 100644
--- a/Engine.Core/Systems/DrawManager.cs
+++ b/Engine.Core/Systems/DrawManager.cs
@@ -2,7 +2,7 @@ using System.Collections.Generic;
 
 namespace Syntriax.Engine.Core;
 
-public class DrawManager : UniverseObject
+public class DrawManager : Behaviour
 {
     // We use Descending order because draw calls are running from last to first
     private static Comparer<IBehaviour> SortByDescendingPriority() => Comparer<IBehaviour>.Create((x, y) => y.Priority.CompareTo(x.Priority));
@@ -29,7 +29,7 @@ public class DrawManager : UniverseObject
             postDrawEntities[i].PostDraw();
     }
 
-    protected override void OnEnteringUniverse(IUniverse universe)
+    protected override void OnEnteredUniverse(IUniverse universe)
     {
         preDrawEntities.Assign(universe);
         drawEntities.Assign(universe);
@@ -40,7 +40,7 @@ public class DrawManager : UniverseObject
         universe.OnPostDraw.AddListener(OnPostDraw);
     }
 
-    protected override void OnExitingUniverse(IUniverse universe)
+    protected override void OnExitedUniverse(IUniverse universe)
     {
         preDrawEntities.Unassign();
         drawEntities.Unassign();
diff --git a/Engine.Core/Systems/UpdateManager.cs b/Engine.Core/Systems/UpdateManager.cs
index 87bf73b..dcf8070 100644
--- a/Engine.Core/Systems/UpdateManager.cs
+++ b/Engine.Core/Systems/UpdateManager.cs
@@ -2,7 +2,7 @@ using System.Collections.Generic;
 
 namespace Syntriax.Engine.Core;
 
-public class UpdateManager : UniverseObject
+public class UpdateManager : Behaviour
 {
     // We use Ascending order because draw calls are running from last to first
     private static Comparer<IBehaviour> SortByAscendingPriority() => Comparer<IBehaviour>.Create((x, y) => x.Priority.CompareTo(y.Priority));
@@ -14,7 +14,7 @@ public class UpdateManager : UniverseObject
 
     private readonly List<IFirstFrameUpdate> toCallFirstFrameUpdates = new(32);
 
-    protected override void OnEnteringUniverse(IUniverse universe)
+    protected override void OnEnteredUniverse(IUniverse universe)
     {
         firstFrameUpdates.Assign(universe);
         preUpdateEntities.Assign(universe);
@@ -26,7 +26,7 @@ public class UpdateManager : UniverseObject
         universe.OnPostUpdate.AddListener(OnPostUpdate);
     }
 
-    protected override void OnExitingUniverse(IUniverse universe)
+    protected override void OnExitedUniverse(IUniverse universe)
     {
         firstFrameUpdates.Unassign();
         preUpdateEntities.Unassign();
diff --git a/Engine.Physics2D/PhysicsCoroutineManager.cs b/Engine.Physics2D/PhysicsCoroutineManager.cs
index e5d47c1..8403594 100644
--- a/Engine.Physics2D/PhysicsCoroutineManager.cs
+++ b/Engine.Physics2D/PhysicsCoroutineManager.cs
@@ -5,7 +5,7 @@ using Syntriax.Engine.Core;
 
 namespace Syntriax.Engine.Physics2D;
 
-public class PhysicsCoroutineManager : UniverseObject
+public class PhysicsCoroutineManager : Behaviour
 {
     private readonly Event<IUniverse, IUniverse.UpdateArguments>.EventHandler delegateOnUpdate = null!;
 
@@ -23,9 +23,9 @@ public class PhysicsCoroutineManager : UniverseObject
         enumerators.Remove(enumerator);
     }
 
-    protected override void OnEnteringUniverse(IUniverse universe)
+    protected override void OnEnteredUniverse(IUniverse universe)
     {
-        physicsEngine = universe.GetUniverseObject<IPhysicsEngine2D>();
+        physicsEngine = universe.FindRequiredBehaviour<IPhysicsEngine2D>();
         if (physicsEngine is IPhysicsEngine2D foundPhysicsEngine)
             foundPhysicsEngine.OnPhysicsStep.RemoveListener(OnPhysicsStep);
         else
@@ -44,11 +44,11 @@ public class PhysicsCoroutineManager : UniverseObject
         }
     }
 
-    protected override void OnExitingUniverse(IUniverse universe)
+    protected override void OnExitedUniverse(IUniverse universe)
     {
         if (physicsEngine is IPhysicsEngine2D existingPhysicsEngine)
             existingPhysicsEngine.OnPhysicsStep.RemoveListener(OnPhysicsStep);
-        universe.OnUpdate.RemoveListener(OnUpdate);
+        universe.OnUpdate.RemoveListener(delegateOnUpdate);
     }
 
     private void OnUpdate(IUniverse sender, IUniverse.UpdateArguments args)
@@ -56,11 +56,11 @@ public class PhysicsCoroutineManager : UniverseObject
         if (Universe is not IUniverse universe)
             return;
 
-        physicsEngine = universe.GetUniverseObject<IPhysicsEngine2D>();
+        physicsEngine = universe.FindRequiredBehaviour<IPhysicsEngine2D>();
         if (physicsEngine is IPhysicsEngine2D foundPhysicsEngine)
         {
             foundPhysicsEngine.OnPhysicsStep.AddListener(OnPhysicsStep);
-            universe.OnUpdate.RemoveListener(OnUpdate);
+            universe.OnUpdate.RemoveListener(delegateOnUpdate);
         }
     }
 
diff --git a/Engine.Physics2D/PhysicsEngine2D.cs b/Engine.Physics2D/PhysicsEngine2D.cs
index 040aabb..a5a3b18 100644
--- a/Engine.Physics2D/PhysicsEngine2D.cs
+++ b/Engine.Physics2D/PhysicsEngine2D.cs
@@ -4,7 +4,7 @@ using Syntriax.Engine.Core;
 
 namespace Syntriax.Engine.Physics2D;
 
-public class PhysicsEngine2D : UniverseObject, IPhysicsEngine2D
+public class PhysicsEngine2D : Behaviour, IPhysicsEngine2D
 {
     public Event<IPhysicsEngine2D, float> OnPhysicsIteration { get; } = new();
     public Event<IPhysicsEngine2D, float> OnPhysicsStep { get; } = new();
@@ -174,7 +174,7 @@ public class PhysicsEngine2D : UniverseObject, IPhysicsEngine2D
         rigidBody.Transform.Rotation += rigidBody.AngularVelocity * intervalDeltaTime;
     }
 
-    protected override void OnEnteringUniverse(IUniverse universe)
+    protected override void OnEnteredUniverse(IUniverse universe)
     {
         physicsPreUpdateCollector.Assign(universe);
         physicsUpdateCollector.Assign(universe);
@@ -185,7 +185,7 @@ public class PhysicsEngine2D : UniverseObject, IPhysicsEngine2D
         universe.OnPreUpdate.AddListener(OnEnginePreUpdate);
     }
 
-    protected override void OnExitingUniverse(IUniverse universe)
+    protected override void OnExitedUniverse(IUniverse universe)
     {
         physicsPreUpdateCollector.Unassign();
         physicsUpdateCollector.Unassign();
diff --git a/Engine.Systems/Tween/TweenManager.cs b/Engine.Systems/Tween/TweenManager.cs
index a35ffa0..4c0b599 100644
--- a/Engine.Systems/Tween/TweenManager.cs
+++ b/Engine.Systems/Tween/TweenManager.cs
@@ -5,7 +5,7 @@ using Syntriax.Engine.Core;
 
 namespace Syntriax.Engine.Systems.Tween;
 
-public class TweenManager : UniverseObject, ITweenManager
+public class TweenManager : Behaviour, ITweenManager
 {
     private CoroutineManager coroutineManager = null!;
 
@@ -73,12 +73,12 @@ public class TweenManager : UniverseObject, ITweenManager
         Return((Tween)tween);
     }
 
-    protected override void OnEnteringUniverse(IUniverse universe)
+    protected override void OnEnteredUniverse(IUniverse universe)
     {
-        coroutineManager = universe.GetRequiredUniverseObject<CoroutineManager>();
+        coroutineManager = universe.FindRequiredBehaviour<CoroutineManager>();
     }
 
-    protected override void OnExitingUniverse(IUniverse universe)
+    protected override void OnExitedUniverse(IUniverse universe)
     {
         coroutineManager = null!;
     }