First, this isn't a standalone. While the story here is complete, there are lots of dangling threads and the author does intend to make this a series. The next story is listed on the author's profile on GR, but it's unknown when or if it will be published.
I really enjoyed this one. The world building could've been better. We know the Blood Legion is a group of sorcerers and mages, and for some reason bleeding increases their power. They seem to have bad reputations everywhere they go but we're not told why. How did they get that reputation? Has it never been challenged? Why has the Legion itself never been challenged or run out? Are they really the only people who ever wear that particular shade of red? I wanted a little more examination into this world but it wasn't there.
There were also a couple of plot holes.(show spoiler)
I did like the characters and how they got along with each other and became friends despite their initial introductions to each other. Niel is perhaps the most flawed and has the most interesting story, which is odd as he's a side character. Luca is a little too sweet given his situation, though his instant infatuation with Rem is understandable once explained. Rem is a vagrant trying to make up for his earlier life of thievery and he's got a mystery in his past that could make for an interesting future story. I like that he doesn't actually fall in love with Luca here, but there is the beginning of love between them.
Good story, and I'm intrigued enough to see where else this author plans to take these characters. Unfortunately, the expected publication date isn't for another whole year. I hope I can still remember this story by that time.