I'm going to disagree with people that Kawaguchi needs a writer; they clearly had a story to tell. What they need is an editor they can trust in to adjust pacing, cut down pages wasted on unnecessary developments, and maximize the ideas actually present.
Otr started out slow with a training arc that did literally nothing – introducing a magic system, heroic vigor, and Sixten, all of which never got expanded upon – then immediately had to rush at a breakneck pace and cheapen the impact of just about every subsequent plot point to cram as much content as possible for reader engagement.
Honestly, if Kawaguchi had gone the Jun Harukawa route of just telling a story even with axes looming, I think they at least would have stayed for 10 more chapters. Though, I suppose they are equally as likely to use that freedom to do a dragged out fight that results in nothing.
Really, that's my main complaint with Otr: everything that could have mattered would have been seriously cool. Except they didn't matter, their coolness was never emphasized, and we just skipped right on to the next thing for Otr to do sword attack #3 with more fire this time.
I really wanted to like this series, and for a few chapters I really did. Otr is at its best after an axe round finishes. The story of Otr that is in Kawaguchi's mind is much better than the story of Otr they put into manga form, as they scramble with the tightrope act of balancing reader engagement and natural development. Every once in a while, the intended story comes up and it's good or even great.
I wish Kawaguchi-sensei good luck with their next serialization.