As many users have already spoiled why this manga is a bit polarising, I'd like to explain both sides instead, so that future readers can decide on their own. Currently at Ch.94. Review may change to reflect any plot development. Please note: everything I mention as pros and cons here can be debated depending on each one's view. Basically, you either love it or hate it.
Why do people like/love this manga?
- It has great art, great story concept, and noticeable character development. You either get hooked by the writing, or fall in love with the characters.
The heroine, Tia, is believably affected by what happened in her previous life. She works on changing her own fate and as a result comes to realise she herself has changed. I loved her and do not blame her for committing any 'mistakes' she made in the past.
Why do people dislike/hate this manga?
- This is where it's pretty much 'make it or break it' for some people: Tia's past life. One fan of this manga recommended to start reading from Chapter 7 and then return to Chapter 1-6, or to treat Ch.1-6 as a prologue somewhat. Basically, distance yourself from the past reality.
Even though many have spoiled it, I'll keep it under the spoiler tag. If you don't want to be spoiled, TL;DR- The Crown Prince and Future Emperor was an abusive ashle. Story points to an ending where Tia eventually ends up with Crown Prince, and readers are split into two camps: He is completely different from the previous timeline (fans) vs He is irredeemable and Tia falling for him is completely unbelievable.
SPOILERS:
Previous Timeline (Ch.1-6) - Tia grew up in a dignified household closely tied to the Royal Family. Due to a (mistaken) prophecy, Tia was raised to be the future empress since childhood. Her dad is a single dad but didn't know how to deal with raising a little girl on his own leading to a cold estranged relationship. She is intelligent, beautiful, and very noble. But her nobility has also restricted her into being a bit too reserved. Tia, yearning for love and affection, falls for the Crown Prince who is for some reason very cold towards her.
Jieun, the actual prophesied 'chosen one', pops back in Tia's world sometime in their teens and supplants Tia, becoming the Empress, while Tia is relegated to 'queen' (basically a consort). Jieun knows nothing about being Empress and Tia ends up bearing the brunt of the responsibilities quietly and dignified as she was taught. She maintains an icy facade and ignores as much as she can while she is repeatedly humiliated by the Prince (now Emperor).
He resorts to physical violence by slapping Tia sometime later due to a misunderstanding caused by Jieun.
He then proceeds to rape her. And while author tries to make it look like Tia is 'only reluctant but eventually gives in because she believes this is all she'll ever get from him' -- I only have this to say: Fck you, bro, it's still rape. He fcks her with malice, hate and disgust. How else are readers supposed to interpret that?
She discovers she's pregnant right when Jieun accepts Emperor's feelings and they do the do. Tia suffers a miscarriage (under really suspicious circumstances, suspect poisoned tea). Emperor abandons Tia in her time of need. It is discovered that Jieun is pregnant with the Emperor's kid, and Tia goes a bit crazy before suppressing it all.
Tia suffers alone and quietly until her father comes to see her and she realises her father loved her all along but didn't know how to show it. Despite loyalty to the crown, he is willing to commit treason and take her away from the palace. He leaves her hopeful she will get out of this hell.
Tia's father is caught, and Tia begs for his life from the Emperor. He makes her lick his boot and kowtow, before revealing to her that he'd already had her father executed. Tia snaps and attacks him, and is caught. She is publicly humiliated and executed.
My advice, personally, is try to get through Chapter 1-6 and then give it a few more chapters to be pulled into the present timeline. If you find yourself falling in love, then keep going and give it a shot.
Present Timeline Spoilers:
Tia wakes up 10yrs old, showing evidence of trauma, and runs into the arms of her father. This starts the first change. The Commander is shown to be a devoted loving father, given the chance. (Honestly one of my favourite heart-warming father-daughter relationships). He is protective but Tia's happiness is still his priority.
She later meets Allendis, a genius and handsome boy, who becomes her first friend. Lots of supporters for this ship due the sweet nature of their budding relationship and the love Tia learns to have for herself.
Turns out Allen is a total Yandere. He's completely different if not facing Tia, and a bit of an obsessive psychopath. But he would never intentionally hurt her is craaaazy possessive and protective of her.
To avoid her fate to marry the Prince and deal with her fear, she learns the sword. She meets Carsien, a rash, hot-headed, honest guy. Also a ton of supporters for this ship because he's honestly a great guy and friend, albeit a bit rough around the edges. He's also quite protective of Tia (but not to an insane degree).
Tia becomes great friends with Allen and Carsien, in a really friend-zone way lol, while pursuing knighthood. She shows signs of PTSD whenever interacting with the Prince. Due to this, the Prince ends up thinking about her a lot.
To somewhat humanise the Prince, author gave him kind of a backstory: He also grew up in a cold household. The only one showing him warmth was Tia's mom (who died in, as of now, unknown circumstances to the reader). Prince's dad, the Emperor, and everyone around the Prince keeps praising Tia and how amazing she is. Prince grows to resent her (which I guess evolves to hate in the previous timeline). But due to Tia changing, he slowly becomes intrigued by her instead.
TL;DR:
If you can distance the Crown Prince of current timeline from the Crown Prince in Tia's past, this will pretty much be a standard good reincarnation story. Worth giving a shot despite all the cons. My rating is from personal taste but I think many would still enjoy this if only they'd give it a shot.
EDIT: This review is for the manga alone. Apparently the novel explained things clearer.