SPOILERS FOR MORT BELOW:

To me, what made Mort so good is the coming of age aspects of it, both for Mort and Death.

Death is having a bit of an existential crisis and trying to figure out what being a human actually is, and the main issue of the story is teenage Mort being unwilling to accept the unfairness of the world and as a result saves the princess who was slated to die.

The genius part to me is when, at the end, when Death and Mort are fighting, upon seeing Mort’s willingness to die for something he believes in, Death finally realizes the most important part of being a human: compassion, and he ultimately redeems himself and achieves some level of humanity by deciding to spare Mort purely out of compassion. To me it ended the story so perfectly; it was an ending that felt earned and ultimately felt very in tune with the themes that the book (and Discworld as a whole).

Thus far what I have liked about the series has ultimately been a rejection of cynicism. The heroes of the story become heroes almost entirely out of their willingness to believe in something.