The story explores the tension between Luka's desire to prove himself as a soldier and his need to belong, i.e. to protect the people that fulfill it.

They're not mutually exclusive, of course. Cue the plot twists!

If you're into unreliable narrators, you'll be hooked by the indoctrination that dominates Luka's entire narration at the beginning. As in - wow, he's a lost cause, but boy am I looking forward to his first subversive thoughts and the decisions that follow.

A bit further into the story, maybe around chapter 40, there's the first major plot point that evinces the overarching theme.

the protagonist becomes figuratively and literally brain-damaged. Yes, the thing that was foreshadowed early on in the story becomes real, but I didn't expect how much it sucks to actually read.

After the rebellion arc ends, many major questions of what transpired are left unanswered as Luka enters a coma. The story flash-forwards twelve years to when his brain is restored. We learn that Luka's sacrifice was mostly invalidated as his loved ones suffer mysterious misfortunes during the time-skip. The story then enters what is essentially a filler arc where Luka is stuck in Bellato working for an alien tycoon and a temperamental, promiscuous idol.