Nothing else to say but if you love a really unhinged MC with extreme Deadpool humour but also a Klein type persona, then this is it for you. Highly recommend. Certified Peak is what I can say 

If you are wondering whether to read this novel just know that this novel is so popular that it got a manhwa adpation, an anime adaptation and its own game. GO IN BLIND AND TRUST ME. It's a masterpiece. Worldbuilding rivals Western literature and don't get me started on the heavy foreshadowing and intricate lore