The Locked Tomb series: 3 volumes (and counting) of unreliable narrators, necromancy, and not quite knowing why I like this series as much as I do

The first book Gideon the Ninth is basically a mystery puzzle video game full of necromancy and POV characters being terrible to each other because they have been so traumatized that they don't quite know how NOT to be terrible to each other.  None of these things should appeal to me.  But I got a huge kick out of this snarky, quirky book even as it killed off basically everyone, including the people I liked.  It was hilarious and ridiculous (in addition to being gross).

The sequel Harrow the Ninth was harder to like (just like Harrow).  I mean, there are unreliable narrators and then there are guilt-ridden and unlikeable narrators who arrange destructive brain surgery for themselves to make themselves even MORE unreliable before the beginning in a book full of even more gross necromancy and characters I don't like, and my time with my preferred narrator was limited.  How do you solve a bunch of mysteries when you've sort of foxed the brain of the person you most spend time in?  And how can this super complicated and sad set of situations be resolves?  Well . . . 

The third book Nona the Ninth was just a delightful breath of fresh air for the most part.  This unreliable narrator had complete memory loss and could have been one of two people and had a bafflingly endearing personality.  The book once again had the sort of end that upends everything that came before it and had the sort of end reveal that required me to read it again immediately after finishing it the first time.  There was very little gross necromancy.  The point of view character was a sweetheart.  The memory loss trope was complicated further by the whole souls and bodies in different combinations.  

I am waiting for the next book to see what curveballs come our way and if certain characters that aren't quite dead do better in any way.