I have looked for hours now everywhere but I can't seem to find the specific book I read a few years ago. It was fantasy about a young boy in a class/caste system that is angry at those above him in standing. He joins the military and trains until he breaks himself, also by using a shadow world where time is different or had an advantage, I'm not entirely sure anymore. I do remember he was obsessed with getting better and defeating those higher than him in standing.
Thank you all in advance!
by the-koolio