I really enjoyed the beginning. While there wasn't much development going on for the mc because he was already the strongest, it was fun watching him explore this new world he found himself stuck in. And I loved his no bullshit personality. He was a blast to read and it really complimented how broken he was. A lot of broken mc who get isekaid into another world is this wishy washy prick who super oblivious to everything, and yet he has all these girls falling onto his dick, so the mc here was pretty refreshing to read. I would say the side characters were much weaker overall, I can only remember the faces of some of them, much less the names. While that is a minus, I'd say that the fun mc somewhat makes up for it.
Now here's where I thought things started to decline. With the introductions of the mechs brings in a whole new power system. And new power systems can help the show if the old one was beginning to grow stale, Jojo is an easy example. But the issue here is the old one wasn't built up upon nearly enough for that to happen. Because Jojo makes an easy comparison, I'll be using that. With hammon being utilized extensively in part 2, there wasn't much Araki could do with it, so the introduction of Stands he breathed a new breath of light into Jojo and has helped it get to 8 parts and still counting. But the issue here is, the magic was explained, mastered, and then barely utilized. The mc learned how to use magic, mastered it in a couple of chapters, and while he does use it, we haven't seen other people use it enough to have grown stale. The introductions of mechs made the magic obsolete and quickly overpowered it. I'd say I'm a fan of mecha anime but it feels like the author just kinda pulled it out of his ass. But I'd say the mechs didn't ruin the show, it just broke immersion and felt a little overbearing.
Now, a good ways into the show, the mc turns into a girl, and I thought this was genius. When he turned into a girl he lost all of his power, hundreds of years worth of it. And I thought this was extremely smart because there was a time limit. He needed his power back, and fast, or else things would get really bad. Where I thought the story would lead is because he doesn't have enough time, he needs to remaster the world's magic system, and with the help of the knowledge from his original world, get strong enough fast enough to stop the conflict. And we get to see the once untouchable mc react to and respond to getting stronger. But this clearly didn't happen. He gets this ring with a water spirit or something like that inside that could level countries. And with the help of that ring, he learns this water magic thing. And while this isn't what I was expecting, the water ring was cool and it should help the mc develop because the water ring trains him in his dream, and serves as a challenge he has to overcome. But no, he gets caught up with this whole political stuff, something something dragon? And some sort of demon power? He uses his demon power to defeat the water spirit, meaning there's jack shit for development. And the whole story starts spiraling out of control. It's hard to keep up with and the whole political aspect doesn't help. This is the point where I dropped it since I wasn't having fun reading it and it just felt like a waste of time.