I didn’t even know that The Black Prism was a series until I’d finished Brent Weeks other series ( The Way of Shadows et al) and it came up in ‘related works’. Reading the summary, I almost wish I’d read them the other way around. Lightbringer seems like more of a traditional epic fantasy (albeit with an interesting magic system, see below) rather than the unrelenting grimdarkness that was The Night Angel books.
One thing that I’ve really been liking about this series thus far is the world building. In particular the magic system. The basic idea is that drafters (magic users) can take light of certain colors–each person has different ranges–and use those colors to do various things. Like you can make a napalm like substance out of red or a solid, smooth surface out of blue. On the down side, drafting too much of a color will eventually drive you mad1. If I knew more about the actual physics of light, I imagine I’d be more annoyed at the technical details, but as it stands, I know just enough to think it’s a really cool idea.