This is at times a funny read, and a times very touching, all mixed with a very interesting mythology.
It's a little bit of Buffy, with a little piece of Supernatural. And thrown in there too is some actual history.
The writing overall is good, but some paragraphs and sentences could use a major overhaul. It is written in first person narrative which can be iffy, but I found no faults in it reading this.
You could also see that it's written by a man a mile away. Especially looking at one scene, where the hero of the story is talking to the love interests boyfriend. No self respecting woman would ever write a scene like that in their books. You are not the boss of her, men.
Despite that, John is very likable. Sig captures you too, and even the side characters finds their own spot in your heart.
The ending leaves you open to a sequel, and I would personally read it.