The Blood Stones

How can something start so strong and just go so low as it continues?
The world-building is interesting, the plot in theory also sounds interesting. The beginning is very strong, however the second half of the book could have used some extra work.
The most prevailing problem is the writing. There are a lot of very, very long sentences that could have easily broken up into smaller, shorter ones. Moreso, there are quite a bit of obvious extrapolations and expositions that add nothing to the scenes.
The time skip feels like the biggest mistake, as it did change the characters only superficially, without having any justifiable reasoning for those changes. The changes can be summed up as brainwashing or trauma. Also, one of the characters has a tense, even hostile, relationship with the main character before the time skip where afterwards they are suddenly best friends, with no explanation.
Overall, interesting idea of a story but very, very poor execution.