The Burning God is the last book in the trilogy so not going to talk much about plot and there won't be any spoilers. I just want to give my general thoughts.
I think this was a fitting conclusion. Heartbreaking but fitting... and dare I say, unavoidable. It is not an easy journey to go through. There is not a moment to breathe. It is all relentless destruction with this one. And page by page, Rin unravels. The trauma, devastation and betrayal she has suffered throughout is impossible to escape.
One complain I have is that it felt like Kuang sacrificed character-driven moments (which were more present in the previous two books) for the sake of the plot. All in all though, an impressive trilogy but not for the faint-hearted.