Salvos is a monster evolution story about a demon in the mortal realm. The action is fun to read, the world is interesting and mysterious, and the characters are eccentric but not annoying (although I'm sure some readers would disagree).
Salvos makes or breaks the story. As a demon, she was born self-aware. She still acts like a child, which leads to most of the other characters underestimating her. Her near-constant immaturity (relative to the humans she spends time with) is broken by moments of cool contemplation, rationality, and surprisingly evocative musings. Applying human standards of growth to a demon is questionable, and the supporting cast hasn't quite learned that yet.
The other members of Salvos' party, Daniel and Edithe, are not particularly fleshed out at this point. Salvos doesn't really care about their backstories, and they're not about to hold her down and explain their motivations to her. They don't quite get Salvos either, despite the amount of time they've spent together. I hope in Book 3, the party grows a bit closer. They still feel a bit much like allies of circumstance than actual friends.
The LitRPG mechanics are simple yet effective in conveying Salvos' evolutions, and her struggles to optimize her build or figure out what her skills do is an entertaining source of drama. She seems to have an instinctual desire to grow in a certain direction, but we don't know what that direction is yet, though the implication is that her unique experiences will influence her evolutions.
Her fighting style is somewhat typical for a LitRPG protagonist, but she has fewer skills and abilities to work with and (as of this review) no magic items that aid her in combat. As a result, the action scenes feature Salvos working within her defined skillset and not pulling a new trick out of her ass every time she needs to win a fight.
This is the author's second work on RR, the other being the witchy isekai Melas. The author has evolved beyond some of the flaws present in Melas, but not all, which is why the Style score here is only 3.5.
My biggest issue with Salvos (and Melas, which I'll review when I finish the second book) is that it's hard to tell who's talking. I need to use context clues or guess, and it's jarring to read a line of dialogue in one character's voice only to have that character respond in the very next line. Then I have to go back and try to figure out who actually said what.
There are smatterings of incorrect word usage, missing punctuation, and typos. Not enough to be distracting, but enough to tell the author was in a hurry. They are, after all, writing three series at once now.
Overall, it's a solid, above average story, and you won't regret reading it if you think it sounds cool.
In a genre dominated by male protagonists, this is one of the rare examples of a competent female lead. Like in most LitRPGs, Elaine experiences a serious spike in power shortly after embarking on her own. Fortunately, it's not due to a rare class or a magic item, but a decision she made early on in the story that turned out to have far reaching consequences: a magical oath.
Her oath is her greatest strength, but also her greatest weakness. She struggles to work with and around it, lending additional tension to conflicts she could otherwise resolve with a thought. She is physically weak with a niche power set, and her restrictions serve to prevent the power creep that so much of the genre suffers from.
Now for the negatives. Elaine can be annoying. Her total age across two lifetimes is 38 at the time of this review, but she still acts like and has the internal voice of a teenager. She's flightly and naive, and seems determined to remain that way no matter her bounding advancements in other areas.
Some of the other characters don't have a unique voice. They are distinctive enough in appearance and personality to stand out from each other, but the speaking lines themselves are muddled, especially when they're packed close together. For example (and I'm paraphrasing), a wizened old man might say "My endeavors have been most worthwhile.", but then two lines later say "Yeah, that kinda makes sense."
Elaine doesn't have a clear goal aside from being a healer. The conflicts that spurred her journey in the first place have all been resolved, and there aren't yet any new ones to take their place. She's just existing in the world and reacting to challenges as they come. One of them needs to go somewhere fast before the story drifts too much further.
Lastly, this is not a critique of the story itself, but a message to the author (who I hope is going to read this). Spoilers within.
You presented the Republic as an inherently sexist society, where women have few to no rights that aren't granted by proxy of their fathers or husbands. Elaine has mostly been spared from this with the exception of a few rude remarks and constant marriage proposals, which you play for laughs.
Your biggest opportunity to make that sexism a major part of your story was the Ranger Academy arc. She was the only girl in an all male class, under consideration to become a Sentinel. I was expecting her to have a horrible time, especially when she started doing Sparring Overwatch instead of Sparring itself (yes, there was a reason, but all the other students can see is that the pretty girl doesn't have to fight). That arc was ripe for abuse not only from her peers, but her instructors.
I think you've forgotten, in your efforts to make these characters likeable, that Elaine is the only character in this book who was raised in a society where women had individual rights. In Remus, that idea is criminal. That's the entire reason she got offered the Revolutionary class, right?
You've done a good job normalizing slavery. Elaine is the only person who thinks it's wrong. The same should be true for the sexism. Elaine should have to prove herself at turn. She should have to earn the respect of characters who would respect her by virtue of her powers alone if she were a man. She should be running into walls such as, for example, not becoming a Sentinel because she would be expected to travel the realm alone, and perish the thought of a woman travelling alone.
So here's my advice. It's too late to change the way everyone has treated her up until now, but she can still hit that wall. Have some Senators challenge her right to be a Sentinel. Give that challenge a lot of support. Have even her allies struggle to reconcile what they know about Elaine with their deeply ingrained prejudices about women. Have someone she trusts tell her she's the exception, not the rule, and have her blow up in their face.
Obviouslty, you don't have to do any of those specific things, but the point is, you need to do something. You can't have this vague sexism sitting in the background until suddenly everything works out because Elaine is such an inspiration. That's insulting to your readers and to women in general. If you do that, I will dramatically throw my phone into the ocean and burn your house down*.
*(I will not actually burn your house down, but I will be thinking about it.)