diff --git a/doc/todo.md b/doc/todo.md
index 064e167..49e468a 100644
--- a/doc/todo.md
+++ b/doc/todo.md
@@ -31,6 +31,7 @@
 - [ ] batch create/instantiate (need benchmark)
 - [x] lock `FilterChange` 
 - [ ] `EntityMngr` `Query`-driven API
+- [ ] `RTDCmpts` = `const EntityLocator* locator + void** cmpts`  
 
 ### maybe deprecate
 
diff --git a/include/UECS/SystemMngr.h b/include/UECS/SystemMngr.h
index 2e04781..935d59b 100644
--- a/include/UECS/SystemMngr.h
+++ b/include/UECS/SystemMngr.h
@@ -2,28 +2,39 @@
 
 #include "Schedule.h"
 
+#include <UContainer/xSTL/xMap.h>
+
 namespace Ubpa{
 	// System Manager
 	// System is a struct with specific function
 	// signature: static void OnUpdate(Schedule&)
 	class SystemMngr {
 	public:
+		void Register(std::string name, std::function<void(Schedule&)> onUpdate) {
+			onUpdateMap.emplace(std::move(name), std::move(onUpdate));
+		}
+		bool IsRegister(std::string_view name) const {
+			return onUpdateMap.find(name) != onUpdateMap.end();
+		}
+		void Deregister(const std::string& name) {
+			onUpdateMap.erase(name);
+		}
+
 		template<typename... Systems>
 		void Register();
 		template<typename System>
 		bool IsRegistered() const;
-		template<typename System>
+		template<typename... Systems>
 		void Deregister() noexcept;
 
+
 	private:
 		template<typename System>
 		void RegisterOne();
+		template<typename System>
+		void DeregisterOne();
 
-		struct SystemLifecycle {
-			void(*OnUpdate)(Schedule&);
-		};
-
-		std::unordered_map<size_t, SystemLifecycle> lifecycleMap;
+		xMap<std::string, std::function<void(Schedule&)>> onUpdateMap;
 
 		friend class World;
 	};
diff --git a/include/UECS/detail/SystemMngr.inl b/include/UECS/detail/SystemMngr.inl
index 595a587..908357f 100644
--- a/include/UECS/detail/SystemMngr.inl
+++ b/include/UECS/detail/SystemMngr.inl
@@ -3,7 +3,7 @@
 namespace Ubpa {
 	template<typename System>
 	void SystemMngr::RegisterOne() {
-		lifecycleMap.emplace(TypeID<System>, SystemLifecycle{ &System::OnUpdate });
+		Register(std::string{ nameof::nameof_type<System>() }, &System::OnUpdate);
 	}
 
 	template<typename... Systems>
@@ -13,11 +13,16 @@ namespace Ubpa {
 
 	template<typename System>
 	bool SystemMngr::IsRegistered() const {
-		return lifecycleMap.find(TypeID<System>) != lifecycleMap.end();
+		return IsRegistered(nameof::nameof_type<System>());
 	}
 
 	template<typename System>
+	void DeregisterOne() {
+		Deregister(std::string{ nameof::nameof_type<System>() });
+	}
+
+	template<typename... Systems>
 	void SystemMngr::Deregister() noexcept {
-		lifecycleMap.erase(TypeID<System>);
+		(DeregisterOne<Systems>(), ...);
 	}
 }
diff --git a/src/core/World.cpp b/src/core/World.cpp
index efd60a8..55b1148 100644
--- a/src/core/World.cpp
+++ b/src/core/World.cpp
@@ -10,8 +10,8 @@ void World::Update() {
 	jobs.clear();
 	jobGraph.clear();
 
-	for (const auto& [id, lifecycle] : systemMngr.lifecycleMap)
-		lifecycle.OnUpdate(schedule);
+	for (const auto& [id, onUpdate] : systemMngr.onUpdateMap)
+		onUpdate(schedule);
 	auto graph = schedule.GenSysFuncGraph();
 
 	unordered_map<SystemFunc*, JobHandle> table;