I'll disagree with the previous reviewer, as I find Eliza to be one of the most interesting protagonists I've read in light novels so far. However, it takes time for the character to be gradually revealed, and it takes time for the plot to be gradually developed, definitely not something you can tell from just reading a few chapters or just skimming the story.
This story is told in Eliza's first person POV, so at first glance, Eliza herself seems like a dry and detached person. But Eliza is actually an unreliable protagonist, and reading in-between the lines will reveal much more about her:
- There is a large gap between her thoughts and her feelings. However, Eliza herself has become not-right in the head due to what she has done, thus fails to realize her own feelings. Actions (and physiological responses, and flashes of thoughts) are louder than words however, and Eliza is gradually shown to care deeply about her people and her army, desperately and insanely so, while at the same time completely ruthless towards those who would harm her people.
- There is also a large gap between her intellectual and emotional age. Her past life made her smarter, but emotionally she is just a child: weak and longing for family and friends deep down, yet unable to recognize her own feelings after hiding her thoughts behind reason to cope with what she's done. In fact, her past life to her are mostly 'someone else's memories', and fade gradually as the Eliza of this world gradually form.
- Finally, there is a large gap between what she perceives and what others think, as she will often use cause and effect to analyse others with suspicion, even when they are displaying genuine goodwill. Worse, she sometimes recognize their intentions, but is unable to accept them.
The fact that she is mostly ignorant of the about the above reveals much of the true state of her mind. To make things worse, her situation won't give a break: rather than a fluffy otome story, this story is heading entirely down a military path, and the protagonist has no choice but to struggle at the front-lines to protect her gains.
There is actually much to like about her: humble and extremely hard-working (not caring about being beat up or throwing up), caring deeply about those she is in charge of, harsher on herself than she is on anybody else. Even with her cold outwards attitude, she shows her concern through action: going easy on those she should be punishing, not minding her subordinates' overly familiar attitude, and later taking the initiative in battle if it means that fewer of her own troops would be killed.
The challenges she faces are numerous (but interesting) however: reforming a devastated land, integrating refugees, navigating the maze of aristocrats and increasingly, facing war directly, and she has to do so from a young age as a powerless child with no cheat, forced to rely on a competent but old guardian who's well above the national croaking age. The national situation is quite complicated and later various intertwined plotlines appear. I have no idea what gives the previous reviewer the impression that the author is making things up on the fly, because the author very early sets down national and geographical elements that continue to play big parts throughout the story (indeed the author actually has a whole bunch of worldbuilding blogs that haven't been translated).
Faced with duties and an unforgiving world, and haunted by memories of the past and what she's done, Eliza herself becomes increasingly... pragmatist. This is more surprising than it seems. Though she still cares more about restoring her lands than the battlefields, the latter is where she is increasingly pulled into, and she kills if she has to, tortures if it'll get results, makes use of her notoriety if it's useful.
In the end, this story is one that you have to read between the lines to get the full picture, but doing so reveals deep characterization and complex plots. Unlike what the genre suggests, it's actually more military-focused than otome-focused (and in the raws, this trend persists even when the school arc starts, so it doesn't suddenly veer into a typical otome story). It takes a while to get into it, but now it's one of my favourite stories.