The recipe is easy and efficient, just put a ridiculously over powered character in a fantasy world with monsters. Well that sound déjà vu. But this one is clever enought to make it well. By that, I mean the universe is kinda mature. The MC can't use his powers all the time to not break the balance between the countries, he may be invincible but he has weaknesses. This is not just a "school boy", he evoles during the story, will eventually have a wife, found a family. The bad points I would put on the series is that beside the MC, his best friend and his girlfriend, you don't really care about others. This problem can't be solved since the MC take all the place and it is what it make this serie's force: The MC is damn Badass, there is a true work on how to show how the MC is powerfull. The "Isekai" looks really out of nowhere, it actually is only used to justify why MC is so powerful. I found is really enjoyable especially since the serie is mature enough to make us fear for the MC's friends.