Then he added one giant robot VS monster scene (they never came back and nobody talk about them after that, the author must have watched pacific rim that day), a fight between a hero and a bad guy with lot of special effects that happen in some evil castle (completly irrevelant and never affect the MC or his tag-along), a girl with animal ears and her beastpeople bandits partners (they all get killed in one shot by the MC too, their screentime apparence is more ridiculous than the team rocket trio), an ancester ghost (because the author must have read a story with one in it), one of the character suddenly kicking ass and taking names using a ancient familial martial art while this character only acted as a princess in distress so far, even against mobs and weaklings, then slaves girls and her horny master (because every isekai story seems to have to have slaves girls in it), then there is a zombie attack arc because there was probably a zombie fad back then, and there is also vampires (because why not after all of this), etc...
