So during the early chapters, the author already shows the FL complicated by weighing the situation if she follow her master order and what would happened if she didnt.

At first I could understand her decision to make such decision even during the duel. However, towards the end of the opening chapters, the authors descrive her thoughts as if she never expected the betrayal. The thoughts are very contradicting from the initial chapters where she was doubting her master and calculating the moves she could made.

I kinda find it frustating, I understand her regret for not chosing the after but not in away she does not see it coming. Bcs she already did. I just think the author have forgotte what she wrote initially.

The ML, Caelus, has also regressed. He figures out almost immediately that Bellona is a fellow regressor. At first, I liked this since it makes for a better match romantically and allows us to skip a bunch of annoying plot beats endemic to regression stories (like the FL not being able to explain how she knows things or having to constantly "earn trust" from people she knew well in her past life). However, it causes more problems than it solves. For one, their obstacles are being treated as rather trivial; this novel has a serious case of "the ML must never lose" so whenever he gets involved, all tension leaves the scene and the FL is reduced to his arm candy. This approach is okay for novels like "How To Get My Husband On My Side" where the tension arises from the FL trying to ally with the ML, but it doesn't work in a novel where the ML already knows everything and is 100% on board with the FL's plans - which Caelus is. The novel briefly teases that Caelus might lock up, entrap or disempower Bellona early on (he makes comments like how he's going to marry her, strip her of her sword, and take his revenge) but it amounts to absolutely nothing. In other words, the regressed ML suddenly enabled "easy mode" for the FL's revenge and there isn't much plot besides. :/

More importantly, it makes absolutely no sense that the FL can't figure out the ML has regressed. Caelus is better at hiding his flaws than Bellona is, but he's still not good at it. Numerous times, Bellona pauses to think: "Huh. He seems more like his future self than his younger self in temperament/skill/knowledge. Oh well, " and just moves on. It's low-key infuriating. She never even wonders how she regressed - like if it were me and I died with a mysterious magic rock in my pocket and regressed, I would at least wonder if it was the rock that did it, but Bellona shows a lack of curiosity OR insight that is simply staggering. By contrast, Caelus figures out it was the rock right away. The FL is otherwise portrayed as intelligent, so why make her look so f*cking dumb unless to forcefully drag out needless drama? Bleh.

It also makes absolutely no sense for Caelus to keep this secret. At first, he justifies it by saying Bellona will run away if he reveals that he remembers his past life, which is reasonable for him to believe: he thinks Bellona very treacherously poisoned her sword in their duel to the death and is genuinely peeved about it. However, this explanation falls apart after their marriage: she definitely cannot abandon the position of Grand Duchess now, and he knows that she's seeking revenge on Impes with her life at stake. She absolutely cannot run away, and feelings aside, Caelus needs to know what happened after he died. He fully expected that Bellona would be able to protect the Emperor and she either couldn't or didn't! He needs to know why! It's already been mentioned that there's a chamberlain close to the Emperor who was instrumental to the assassination, and Bellona is wilfully choosing to hide that information while Caelus is wilfully choosing not to seek it - for no good reason.

This novel is already uncannily similar to another novel called Adonis (talented swordswoman with crimson hair, ML is a member of the imperial family with black hair and gold eyes who she's obsessed with sparring with, etc.), but I'm really disappointed that it also shares what I considered to be Adonis's worst flaw: the ML and FL needlessly hiding their regressions from each other for boring, tensionless drama. It's inexcusable.