diff --git a/lib/wal/CMakeLists.txt b/lib/wal/CMakeLists.txt
index 2e6dff87..81d730f2 100644
--- a/lib/wal/CMakeLists.txt
+++ b/lib/wal/CMakeLists.txt
@@ -13,8 +13,6 @@ add_library(wal
 	sources/Scene/SceneManager.hpp
 	sources/Scene/Scene.cpp
 	sources/Scene/Scene.hpp
-	sources/Renderer/Renderer.cpp
-	sources/Renderer/Renderer.hpp
 	sources/Events/EventManager.cpp
 	sources/Events/EventManager.hpp
 	sources/Exception/WalError.cpp
diff --git a/lib/wal/sources/Renderer/Renderer.cpp b/lib/wal/sources/Renderer/Renderer.cpp
deleted file mode 100644
index a77f2515..00000000
--- a/lib/wal/sources/Renderer/Renderer.cpp
+++ /dev/null
@@ -1,13 +0,0 @@
-//
-// Created by Zoe Roux on 2021-05-14.
-//
-
-#include "Renderer.hpp"
-
-namespace WAL
-{
-	void Renderer::render()
-	{
-
-	}
-}
\ No newline at end of file
diff --git a/lib/wal/sources/Renderer/Renderer.hpp b/lib/wal/sources/Renderer/Renderer.hpp
deleted file mode 100644
index af6fbd27..00000000
--- a/lib/wal/sources/Renderer/Renderer.hpp
+++ /dev/null
@@ -1,16 +0,0 @@
-//
-// Created by Zoe Roux on 2021-05-14.
-//
-
-
-#pragma once
-
-namespace WAL
-{
-	//! @brief The renderer class used to display things.
-	class Renderer
-	{
-	public:
-		void render();
-	};
-}
diff --git a/lib/wal/sources/System/System.cpp b/lib/wal/sources/System/System.cpp
index e1cc2ec0..82f7fe11 100644
--- a/lib/wal/sources/System/System.cpp
+++ b/lib/wal/sources/System/System.cpp
@@ -12,4 +12,7 @@ namespace WAL
 
 	void System::onFixedUpdate(Entity &entity)
 	{}
+
+	void System::onSelfUpdate()
+	{}
 }
\ No newline at end of file
diff --git a/lib/wal/sources/System/System.hpp b/lib/wal/sources/System/System.hpp
index 76a609e8..3813e216 100644
--- a/lib/wal/sources/System/System.hpp
+++ b/lib/wal/sources/System/System.hpp
@@ -30,6 +30,9 @@ namespace WAL
 		//! @remark This should be used for Physics, AI and everything that could be imprecise due to float rounding.
 		//! @param entity The entity to update.
 		virtual void onFixedUpdate(Entity &entity);
+
+		//! @brief A method called after all entities that this system manage has been updated.
+		virtual void onSelfUpdate();
 	protected:
 		//! @brief A system can't be instantiated, it should be derived.
 		System() = default;
diff --git a/lib/wal/sources/Wal.cpp b/lib/wal/sources/Wal.cpp
index f1c84e72..569743aa 100644
--- a/lib/wal/sources/Wal.cpp
+++ b/lib/wal/sources/Wal.cpp
@@ -13,31 +13,31 @@ namespace WAL
 
 	SceneManager &Wal::getSceneManager()
 	{
-		return this->_scenes;
+		return this->_sceneManager;
 	}
 
 	void Wal::run()
 	{
 		auto lastTick = std::chrono::steady_clock::now();
-		std::chrono::nanoseconds dtime(0);
+		std::chrono::nanoseconds fBehind(0);
 
 		while (!this->_shouldClose) {
 			auto now = std::chrono::steady_clock::now();
-			dtime += now - lastTick;
+			std::chrono::nanoseconds dtime = now - lastTick;
+			fBehind += dtime;
 			lastTick = now;
 
-			this->_update(dtime);
-			while (dtime > Wal::timestep) {
-				dtime -= Wal::timestep;
+			while (fBehind > Wal::timestep) {
+				fBehind -= Wal::timestep;
 				this->_fixedUpdate();
 			}
-			this->_renderer->render();
+			this->_update(dtime);
 		}
 	}
 
 	void Wal::_update(std::chrono::nanoseconds dtime)
 	{
-		auto &entities = this->_scenes.getCurrent().getEntities();
+		auto &entities = this->_sceneManager.getCurrent().getEntities();
 
 		for (auto &system : this->_systems) {
 			for (auto &entity : entities) {
@@ -47,12 +47,13 @@ namespace WAL
 				// TODO handle dependencies.
 				system->onUpdate(entity, dtime);
 			}
+			system->onSelfUpdate();
 		}
 	}
 
 	void Wal::_fixedUpdate()
 	{
-		auto &entities = this->_scenes.getCurrent().getEntities();
+		auto &entities = this->_sceneManager.getCurrent().getEntities();
 
 		for (auto &system : this->_systems) {
 			for (auto &entity : entities) {
diff --git a/lib/wal/sources/Wal.hpp b/lib/wal/sources/Wal.hpp
index c8dd535c..ea72eb05 100644
--- a/lib/wal/sources/Wal.hpp
+++ b/lib/wal/sources/Wal.hpp
@@ -10,7 +10,6 @@
 #include <typeinfo>
 #include <Exception/WalError.hpp>
 #include "Events/EventManager.hpp"
-#include "Renderer/Renderer.hpp"
 #include "Scene/SceneManager.hpp"
 #include "Entity/Entity.hpp"
 #include "System/System.hpp"
@@ -22,13 +21,11 @@ namespace WAL
 	{
 	private:
 		//! @brief The scene manager that allow multiple scene to work together.
-		SceneManager _scenes;
+		SceneManager _sceneManager;
 		//! @brief The event manager
 		EventManager _eventManager;
 		//! @brief The list of registered systems
 		std::vector<std::unique_ptr<System>> _systems = {};
-		//! @brief The renderer used to draw entities
-		std::unique_ptr<Renderer> _renderer;
 		//! @brief True if the engine should close after the end of the current tick.
 		bool _shouldClose = false;