So after Howard Taylor's glowing recommendation, I picked up the Promise of Blood ebook for $2 the other day. It's a pretty good book! Some really fun characters, great worldbuilding, and solid plotting. If you like epic fantasy, and especially if you think adding gunpowder-based magic as a foil to more traditional elemental magery is interesting you will enjoy it.
It fails the Bechdel test. Like, REALLY badly. There are five , maybe six named female characters. None of them speak to one-another on page. Only one of them gets more than 1-2 lines. And the one we see the most is a mute. And also a Noble Savage With a Life Debt. And also the teenaged maybe love interest of the older main character. And don't get me started on what should have been the second most prominent woman in the book, but who was barely seen and whose most prominent decision (cheating on her fiance) happened before the start of the book, and was written off by every man in it as not her fault because /he/ seduced /her/, robbing her of any agency and and and blah.
So if that stuff bugs you, you may want to skip it. But the magic system and world building really are very good, especially for a first outing. I'll probably pick up the sequel, which seems to be coming out this May.