Cioran

I think ML’s father was the usurper-emperor who died in the first episode. ML was there when he died and dictated his will.

I feel the same way about the ML.
At the core, he’s a tragic figure — a hopeless romantic who chooses love, or rather a passionate obsession, and, as he admits himself, puts everything on the line. He becomes vulnerable and honest in front of the FL.
The female lead is written in such a way that the ML seems more like the victim — both of his own obsession and of the cunning FL. He knows he's obsessive and driven by intense emotions.
Everything he does is for her, and he’s ready to die for her. He’d probably even accept death at her hands with a kind of gratitude and quiet emotion. Również pozdrawiam!

In my opinion, the female lead has a certain weakness for the male lead — she’s drawn to him, even pities him a little, and understands his twisted intentions. But she also believes they’re both doomed if they stay in their sinful relationship. That’s why she keeps choosing freedom and calmly plots her revenge on him. She weighs everything with a cool head — her feelings and doubts don’t cloud her judgment. Even the male lead’s mother, who fears and hates him, admits with a hint of admiration: “I underestimated you. You’re just as dangerous as my son.” Unless the mystery surrounding her origins shifts the dynamic of their romantic entanglement, we’re probably headed for a tragic ending for him — and a happy one for her.
This really is a strange case of a mini-drama. It’s neither a romance nor the story of a cruelly exploited woman and a repulsively depraved man. It’s probably best to see it as the heroine’s bizarre, perverse dream.
Still, I’ll shamelessly admit — I’m really enjoying it.

The male lead has another sister, but it turns out she’s actually his half-sister. Her name is Pei Zi Qi, and she’s married. It seems her father is the mother’s long-time lover. The male and female leads are not biologically related.

Yes, he found out in episode 9.

It seems to me that it might have been about this drama: https://kisskh.at/752483-shi-xin-chuan

The character of the FL is quite intriguing, especially her inner monologues. She's a self-aware protagonist who, so far, hasn't been intimidated or deceived by the ML’s passionate declarations of love. The dynamic between abuser and victim is portrayed rather well at this point. The FL has ambivalent feelings toward the ML, but she’s also bravely fighting against developing Stockholm syndrome.
Meanwhile, the ML, true to his role as a manipulative abuser, is not only cruel but also occasionally tender and caring. We’ll see whether the screenwriter chooses to romanticize this toxic bond or allows the victim to ultimately triumph over her tormentor and break free from the cage the ML has trapped her in.

The main cast members are of a similar age. The actor is one year older than the actress.

When you say "Many women often choose those guys even if they're not aware they're doing it. Many are drawn to those men and then complain about why they're treated poorly. Meanwhile, you have the nice guy waiting in the friend zone", you're generalizing too—just like I did earlier—and you're not only speaking for yourself.
I just draw a clear line between fiction and real life. What I expect from guys day to day is totally different from what I like in fictional characters. Toxic boys? Only on screen or in books. With this drama, I’m letting it pull me in—but just while I’m watching.
To conclude, dramas can influence how we perceive romantic relationships in both positive and negative ways. That's why it's important to keep reminding yourself that this isn't real life—to stay safe.

Yes, this is something for fans of the genre. We know exactly what we’re getting, and we don’t want it to be anything else. The standard ingredients of this kind of drama are all here: forbidden love and dark desires (in this case, there’s erotic tension between “siblings”); elaborate torture scenes (like our FL being whipped with thorny roses by a princess insanely jealous over the ML); a game of appearances (who’s really in control, and who’s just pretending?); a play on imagination; and characters with the kind of strength we, the viewers, lack. This is no heartwarming tale—and it’s not meant to be taken too seriously, either. So far, it’s pretty good—at least for me.

A warning for the “innocent” and sensitive viewers:
Many Chinese mini-series carry a heavy, almost claustrophobic, sadomasochistic vibe and follow a rather old-fashioned approach to portraying male-female relationships — and that’s precisely where their charm and emotional pull lie. You won’t find warm, empathetic characters here. Some viewers will find this alluring; others might be completely put off.
The title Once Upon a Dream already hints at what we’re dealing with — unspoken, hidden, even shameful desires. Our “virtuous” female lead is having erotic dreams about the male lead. The cage scene (which was actually quite beautiful) can come off as romantic and tempting, but only because it unfolds safely on screen.
To me, these kinds of dramas create a relatively safe space, even while exploring dangerous temptations and allowing for guilt-free fantasy. These obsessive, possessive male leads with their attractive faces are seductive because they’re fictional. That doesn’t mean we’d want to date someone like that — or even bump into them — in real life.
That said, in this drama, the male lead doesn’t seem one-dimensional, and the female lead isn’t just a helpless victim either. Let’s see how the story unfolds — and who’s really hunting whom...

He could desperately try to earn her forgiveness, but still be unable to forgive himself for what he did to her. In the current situation, it’s she who’s practically begging for his apology. Either way, FL is at a disadvantage here. Honestly, I’d almost prefer if the couple broke up over some ridiculous misunderstanding rather than under such serious circumstances. Especially since he had already humiliated her before by unjustly firing her from the lab. I really don’t understand why a light-hearted comedy needs to resort to such extreme measures just to create conflict between the lovers.

The series seemed to have potential—not for a sweet romance, but for something darker and slightly twisted. There were hints of this in the dialogue and scenes like the male lead traces his finger seductively over the female lead’s wounded back and pointedly warns her that he is no gentleman. It ends with the ML, after the marriage, dutifully serving tea to the woman like a devoted housewife, while she focuses almost entirely on building a female alliance and seeking revenge. Maybe some viewers are satisfied with how the plot developed, but I count myself among the disappointed ones.

In The Double, the lead actors delivered much stronger performances. They managed to convey the depth of their emotions simply by looking at each other.

I think that the writer intended this to be a romance, but one of the last-minute variety. A similar thing happened in The Double. For several episodes, the main couple slowly but steadily develops their feelings for each other, and eventually, there’s a love confession and union. However, while The Double managed to make the romantic relationship feel completely believable, thanks in part to the excellent performances of the leads, here something didn’t work, judging by most viewers’ reactions. Some people don’t even want a happy ending anymore. For me, their marriage will probably remain a marriage of convenience until the end of the series—a kind of mutual exchange of favors. The writer portrays women in a modern way, but when it comes to love, he turned out to be a traditionalist. He deprived us of romantic moments. It seems that the love confession will happen in the 27th episode, but for me, it’s already too late.

She is blinded by the lust for bloody revenge, and he is blinded by his love for her. This makes them both incapable of making rational decisions.

I value your nuanced perspective; it made me reflect. And thank you for being willing to share such a different point of view. It seems to me that you’re simply a deeply engaged viewer of this drama. However, I admit that I remain a more shallow viewer here and don’t feel emotionally connected to the FL character.
I watch Chinese costume dramas mainly because I want to “take refuge in not thinking.” I started this series hoping for a romance that would be “passionate” by Chinese standards. There’s a lack of romantic excitement in my life, so I look for it on the screen. My hopes were disappointed, which probably also affects my more negative attitude toward the characters in this drama.

Maybe, however, we should allow others to express their own feelings and freely interpret the motivations and behavior of the characters. For some, the heroine will be a clear-cut villain, while for others, a complex personality. There is no single correct interpretation of a fictional series. When it comes to art, there is no absolute truth. Your observations are interesting. However, some people don’t feel the need to analyze everything in detail and are simply looking for enjoyable entertainment, not psychological depth.
I enjoy reading the discussions here because viewers’ opinions and interpretations are so diverse. To me, the FL is too unwavering, almost caricature-like in her impulsiveness and exaggeration. However, I understand that someone else might perceive her entirely differently and see something completely different in her. I just don’t understand why anyone would try so hard to prove others wrong. Such fierce defense of fictional characters is beyond me. But that’s just my humble opinion.

All of this, however, happened before he proposed to her. After the wedding, he keeps the promise he made to her. Besides, she consciously agreed to be a shield for his family. Not selflessly. I understand her distrust and caution. She will probably help him at some point and have her own heroic moment of saving his family. For now, though, he is the more devoted husband or at least her loyal ally.

Yes, they are using each other, they have their own goals, but there is no balance between them. If it weren't for ML's interventions, our brave girl would have been dead long ago. For now, FL is benefiting more from this marriage than ML. He even serves her tea. His family is in even greater danger than before the wedding. And some people here seem to forget that we are talking about fictional characters. Therefore, there's no need to defend the FL character at all costs, as if someone were insulting someone's mother. It's just entertainment, and quite decent at that.