He didn't switch his writing style, He just chose to not edit the AI written Chapter.

I like this story more than those other DxD fanfic where the MC just is spouting bulshit like I am a man of character but they can't help thinking with their dick. I like the way he didn't skip the childhood Arc it gave the old isekai light novel vibes when the MC grinds from childhood. plus I Hope the author stops using AI to enhance the story, it is okay to use AI to correct grammar and Spelling but enhancing the story is making it more life less. In the beginning chapters the conversation and inner monologue and explanation seems natural and thought by a normal person reincarnated in DxD but later it just use AI to fill in the gaps and explanation made it like some history book than a novel which should make us feel and imagine the surrounding just by reading the words. Any way I am looking forward to the future chapters. If my comment offended someone then sorry otherwise you can just ignore it.😑😑