Was chapter 13 the final part of Katabasis?
Nope. Not by a long shot. Katabasis has about 100k words left in it. There's quite a lot of plot and character development to go before the final part will be posted.
I'm just currently suffering from the worst case of "I feel like everything I write is garbage and hate it" which results in me writing 200 words in one sitting, deleting at least 100 of those words and then staring at the computer for an hour. It's slow work, and I've let myself get distracted in research rabbit holes, which while relevant for the story as a whole isn't important for the chapters that are currently holding me up.
I am probably going to just have to close my eyes and submit something I'm not completely happy with for the next couple of chapters, and let you guys read the damn thing instead of stressing myself out over something that is holding the rest of the story back.