Reborn to Master the Blade: From Hero-King to Extraordinary Squire is an isekai-fantasy light novel written by Hayaken. It was adapted into a 12-episode anime by Studio Comet.

I will cut to the chase.. this anime sucks.
I first saw it while overviewing the Winter 2023 season, the premise was generic, but I did get interested in its gender-bending gimmick. It sounded like fun. I was open to giving it a try, especially when it had an above 75% score.. for some reason?

I thought it would be some dumb fun like Season 1 of How Not to Summon a Demon Lord. Nothing great, but fun enough to keep you entertained. But nope it is incredibly boring, so boring I would rather watch Naruto filler. This is the type of anime you use as examples when trying to list bad Isekai to someone.

This is a generic power fantasy. A reincarnation story of an old king reincarnating as a busty silver-haired girl named Inglis "Chris" Eucus. His main goal in his second life is to become the strongest person possible... but it’s so booooring.. It reminded me of The Strongest Sage with The Weakest Crest, as each episode kept getting duller and duller.

World-building? There was world-building?
Umm, let's see monsters attack people, some people get crests on their hands to use magic but our OP MC can gather mana from the atmosphere or some shit. Some supremacists called highlanders look down on common people, and some resistance groups forms trying to kill the highlanders. While our MC goes to school and wants to fight fight fight.

Chris is one of the worst main characters I have had the displeasure of watching. Watching her is the equivalent of self-harm to the brain. She is dumber than Goku from Dragon Ball Super and her key personality trait is that she loves to fight.. and she reminds you over and over again. More in a single cour than a majority of battles Shonens.

She is incredibly smug with no humility or weaknesses. There is no purpose to her even being gender-bended into a female body, except for an internal monologue or two.

Incredibly powerful no less. She no diffs every single character in the series. Despite being called Reborn to Master the Blade, she never uses a sword! Instead just throws her hands and shoots Kamehameha waves as a baby. Whenever I hear the term Mary Sue, Chris will pop into my brain from now on.

The side characters are not worth mentioning in the slightest, all of them feel like Oblivion NPCs that you can summarize in a single sentence.

The production values are what you usually see out of J.C. Staff's C team.

The art style is appealing to me, but the animation is bad. Punches have no weight behind them, half of an episode you have characters just moving their lip flaps in a room with uninteresting dialog, and the CGI for the monsters is exceptionally bad.

The sound design wasn't anything noteworthy, and it felt like even the voice actors just wanted to quickly record their lines and bail.. but at least the opening is good.

Would I recommend this anime? Hell no.
It is boring, uninspiring, and has a truly terrible main character.