Ann Leckie's Ancillary Justice

There's so many good bits and little shiny details in this epic redemption journey. In the past, a simple occupation mission by an atrocious all-conquering invasion force goes awry with a mysterious conspiracy coming to a head. The protagonist is an AI ship consciousness multiply embodied in enslaved human soldiers. A crisis builds under the watchful eye of an empress that rules from within thousands of bodies.

In the present, the aftermath of the crisis is our protagonist singly embodied, troubled by the atrocities it committed and dedicated to a hopeless mission of vengeance.

There is a lot of dealing with a... not an untrustworthy narrator but an extremely neurodivergent naive narrator. Lots of fun gender issues and language issues that present as interesting puzzles for the reader.