What has been the hardest book for you to write? And the easiest? Was this particular book difficult to write?
Hardest was by far A Memory of Light. Easiest was probably Alcatraz vs. the Evil Librarians, which I discovery wrote and did half as a writing exercise to keep me from burning out while working on the Mistborn trilogy.
This one was middle of the road. Most of it was easy, but the ending in the first draft didn't work and required a lot of beating my head against the wall until I was able to get things to click together.