i zoned out by the 3rd chapter. that retsu isn't retsu and every character introduction bores the fuck out of me. in the main baki series you get an interesting monologue on the philosophy of some martial art, a build-up, a showdown, and the ever so frequent visitation from Yujiro himself to amp up the main storyline behind Baki beating the shit out of his dad.
retsu isekai had none of those. first 2 fights he get in are with no name jobbers whose only there to reinforce that Retsu can kick the shit out of people. there's no philosophy, build-up, or any of the usual Baki flair. it's like some guy's first attempt at an isekai and his only saving grace is that he gets to officially use the character's name to sell his shitty work.
i will reiterate that the retsu in retsu isekai is in no way retsu. he did not have his leg eaten and chopped off by musashi to only revert back the arrogant mess he was in the original Grappler series.
the art isn't even that great. it's just barely better than the first Grappler series, but that's not a high bar, and that series has its insanity going for it. i mean, Grappler Baki introduced fucking GAIA. retsu isekai had some mysterious fire magic lady who had the shit kicked out of her in half a chapter.
