This isn't the first time we've read about a holy knight from a secret order who thought they were the good guy but then discovers that they're also killing innocents. Reason enough to abandon the order and try to disappear into normal society, only to pick up the sword again in order to right all the wrongs. But Stewart manages to breathe new life into the trope with colorful characters and some great world building. This is an urban fantasy with magic, mythological beings, spy tech, and some LGBTQ+ Pride.

Aaron Conner was recruited into a secret Catholic order as a boy. They trained him as a Spirit Knight to fight the Otherworlders, who fall into our world through several thin spots around the globe. They are the basis for many of the myths around the world, such as trolls in Scandinavia or djinn in the Middle East, and some of these Otherworlders are cursed to feed on human souls to keep themselves alive. Connor had no problem dispatching these Feeders, but most Otherworlders are simply trying to build a life in their new reality while the order tries to kill them. So Aaron abandoned the order and attempted to disappear, hoping that they will leave him alone. He's content as a bartender with a lesbian best friend and a crush on a pretty lawyer who has one of the penthouses in his building. Then he makes the mistake of taking a better paying job at a private club that expects discretion above all and Aaron discovers that several of the patrons are Otherworlders. It's not a problem until he finds some part-bloods killing a girl to imitate Feeding. This starts a cascade of events where he must again call on his Spirit Blade for defense, as well as to take down the ancient and powerful Feeder living in Huron City. He's aided by a troll engineering whiz who also carries ordinance meant to be mounted on armored vehicles, his best friend the token ordinary human, and the pretty lawyer who also has a crush on him.

Overall, I liked everything about it, even if some of it was predictable. The magic has some common elements with the magic in the Starship Mage series, although it's a lot more low key in this book. There's a nice variety of beings with some being friends, some evil, and a few honorable types caught in bad situations. The weapons and tech are combined with the magic for some fun gadgets. Spirit Blade is available in all formats (still pre-order on Audible) and is included with Kindle Unlimited.