I've just finished a massive literary edit on The Wizard and the Warlord by M.R. Mathias. This is the third book in Mathias's Wardstone trilogy and is a truly epic tale.
The twists and turns, characterisation, and sheer breadth of world building in this series are astonishing. Those things, along with literally hundreds of character names, demons, and all manner of strange creatures, make it a potential editing nightmare. Suitably forewarned, though, I compiled a Wardstone dictionary during the first two sweeps of the text and was able to reference that throughout the final edit.
It's not very often I actually enjoy a book I'm editing. Editing, by its nature, is a very exacting process and I tend to hate whatever I am working on at the time. When I look at the finished books again some months later, my outlook has changed and I usually really like them. With this edit, however, I found myself enjoying the story and the humour at each stage.
I've worked on a few Mathias books now, and have read a couple of others. Without a doubt, The Wizard and the Warlord is his best work to date.