Overall this was an enjoyable read.
It's a bit clichéed, a little shallow, and rich in cheesiness.
I have no clue how this book got tagged as "Dark" here on Goodreads. It's anything but.

The whole story is unoriginal but the execution is good enough to be enjoyable anyway.

Onto the issues, I had with it.

The book tries to go for shades of grey but instead only manages to badly disguise its very simplistic black and white nature.

The author tried to cram too many traits into the MC, some of which conflict rather badly.
She is supposed to be the dejected, emotionally withdrawn, and hopeless loner that fears being hurt again but at the same time she emotionally attaches immediately which gets her hurt again so she again acts out her withdrawn loner persona. Her thoughts and her behavior constantly contradict each other in this way which makes her seem impulsive and irrational at best which is clearly not what the author was going for.
She is supposed to be this badass fighter with lots of experience that killed hundreds of people but at the same time, the author tries to give her the innocent goodie-two-shoes trait. She is a walking contradiction but not in a good way.

Something that annoyed me a bit but is probably mainly due to the audiobook narrator is the MC's tendency to cry. The narrator read passages where tears were mentioned in this sobbing-so-hard-I-can-barely-speak voice. Her voice acting in itself is fine but it's way too much and she even does it in scenes that explicitly mention that the MC sheds tears silently with no other signs of distress. That was the impression I got from the MC in general. A silent crier, not those melodramatic heaving sobs.

The author temporarily ignores internal consistency so she can write impactful action scenes exactly as she imagined them but forgets that the resulting cognitive dissonance destroys immersion which in turn spoils the scene's impact. As a result, some of the most important scenes suffer from entirely unnecessary contradictions.
Apart from this, there are quite a few mostly minor inconsistencies in general as well.

We have learned basically nothing about the very prevalent magic in this world which seems very complex but is very handwavy at the same time.
There hasn't been a major plot hole so far but it's only a question of time before the author gets tangled in all that throwaway magic.

I expect many of the flaws that only started to show in this book and are mostly minor so far will blossom into much bigger problems in the next one. ( )

Thoroughly enjoyable! Sloane finds herself dead and transformed into a creature who needs to drink blood to survive. She turns into a vigilante of sorts, only killing and feeding on the evil and criminal members of society. When she encounters a group of people who, like her, have their own paranormal gifts, she joins forces in tracking down a killer. Night Watch has action, suspense, humor and, a little bit of steam. I'm looking forward to the next book in this series. ( )