System Creator System: I Can Create Systems!

A bored teenager, after praying to god for something to relieve his boredom, got his prayers answered. It just so happens that Systema Kami, the God Of Worldly Systems, was recruiting an assistant!-Ding![System Creator System has been integrated into the host's soul!][First Task: Create a soul parasite type system.][Second Task: Grant the system to any living being.][Third Task:]After receiving the System Creator System, Keith embarked on a journey to becoming the greatest System Creator!Training System, Leveling System, Hero System, Villain System, and even Harem System! The possibilities are endless!When he received the system, some of the secrets of his world were revealed to him!Keith McDowell: System, are you serious? There is a book titled "End Note" that has the power to bring the end of anything. And it just so happens that a regressor obtained it which should have been mine?[Yes.]Keith McDowell: And my schoolmates have been summoned to another world as heroes to defeat the demon lord and save the world?[The creator is right. Not only that, there will be a dimensional gate that will open after a month.]Keith McDowell: Finally! My thirst for entertainment can be satiated!In other words, this is none other than the journey of a young man who wants to entertain himself, whatever it takes!