As I said to someone on Twitter, the reason I didn't use a pun about Hel is that it's not her story. It's Durkon's. And Sigdi's. I wanted a title that reflected them, and the nice thing about "dwarf" is that it doubles to also mean "to make look small in comparison" such as, say, next to a god, or an infinite void filled with gravestones. So it also reflects this book's place in the overall story, which is to zoom out and show that it's a much bigger problem even than they thought it was.