This manhua is SHOCKINGLY good for a relatively regular shoujo first arc and a premise that seems hard to work with if you're not going full out mecha. There are problems here and there, but I'm keeping this rating at 10 stars because I think it deserves to be read.
Each character is fleshed out with goals and stories of their own which are interwoven with the bigger conflict at hand, while giving each storyline an ample amount of time to develop between plot points. The main character herself is also such a great example of the amazing character development that occurs - having grown considerably from the wilting flower in the first chapter to a fitting protagonist who can stand her ground.
The romance is also quite well-done - the main male lead and the female lead have chemistry right away that, while it began with the typical manhua "female lead hates the extremely arrogant/rude male lead", quickly moves onto something more genuine as they discover more about each other and go through hardships together instead of pulling the stereotypical almost one-sided "she falls in love with a jerk anyways" that is so typical in shoujo manhua.
Speaking of genres, one of my favourite thing about this series is its blend of shoujo & shounen elements. With the raws at around chapter 600 at the time of writing this, the action plot dealing with war & espionage obviously plays a huge part, but at its core it is introduced as a shoujo sci-fi rather than a purely shounen sci-fi, and honestly I would love to see more series like this: an pretty serious action focused story whose demographics are more shoujo based than shounen, but at the same time is willing to sideline the romance for more serious parts of the plot.
Of course, this series isn't without mistakes. Some of the plotlines may feel convoluted because there's too much happening at the same time and some of the drama is way too amped up and drags on for too long (such as the one that happens with the male lead in chapters 140-160...). I myself wasn't a huge, huge fan of the artwork, and the female lead in the first arc, while she is indignant, may begin to feel like a somewhat powerless heroine at the whim of an annoying male lead (thankfully the later story redeems this by tenfold). But all in all, I read all the translated chapters in one sitting and I still think it's a pretty fantastic and unique manhua for people who love a good shoujo but also loves a good action series. Mystic Crescent Scans is unfortunately inactive, but there is currently someone translating on their own along with Mangatoon's translations (locked by paywall, of course).
Even if you're unsure of this series, I definitely think reading the first couple of chapters couldn't hurt!