Book of the New Sun (these days divided into "Shadow & Claw" and "Sword & Citadel" which unfortunately makes them sound a lot more generic than they are). Certified classic banger in the science fantasy genre, known for its unreliable narrator, subtle worldbuilding and being WILD on a second read
Right! I listened to a podcast where they talked about it. Tried to keep up with the reading but life got in the way. I look forward to reading it some point. It and more Malazan. Working on the Flat Earth by Tanith Lee right now.
And I mean "radically change the way you view the novel" levels of wild, like "wait was that his long lost sister and he just didn't notice?!" as a lesser revelation (and also funny ones like him confidently stating a rite of the beastmasters and you realize he misinterpreted "animal husbandry")