The author says:

Christian Historical Fiction set in 1st Century Roman Empire. The name listed on the cover is that of the narrator of the account, Helena Mithridates Kleopatra, who is also the main protagonist. The mask is sort of the “McGuffin” of the tale (the blood on it, however, is merely symbolic–the mask is never “bloody” in the story). I chose this design because it was simple, direct, and evocative. I made sure the typology was legible at any size. The book is nearly 200k words, so I won’t test your patience with a synopsis. These comments should be enough to go on for the purposes of critiquing the cover.

Nathan says:

Very legible, very clear.  However, I see two big problems:

1. It says “Roman” very clearly, but doesn’t say “Christian” at all, no matter whether you mean that it’s about 1st-century Christians, or it’s aimed at Christian readers, or both.  I don’t know if there’s a simple iconographic fix which is both historically accurate and evocative to a modern audience (I don’t think the fish symbol has enough umph to do the trick); you may have to resort to a subtitle like “A Novel of First Century Christianity.”
2. The first-person narrator’s name is all well and good, but where is your name?  Are you going to be anonymous? Is your name going to be present in the Amazon listing?  Unless you intend to be completely anonymous (which is an arguable choice), it’s your name that should be there, not the character’s. (The other problem is that the protagonist’s three-part name doesn’t immediately seem like a single name, given that “Kleopatra” seems like a first name to most modern folks — when I first saw it, I thought it was a list of three separate characters.) You might get away with “The Tale of Helena Mithridates Kleopatra, as told by XX,” but that seems like a Rube Goldbergian workaround, especially if you’re also going to use a subtitle to clarify the Christian angle.  I think you should just do without naming the protagonist on the front cover.

Other comments?

The author says:

This is the beginning of a fantasy series set in the modern oceans, where the last merpeople in existence live in secret, struggling to survive. Over the series, the mers come out of hiding and reshape their relationship with humans through war and peace. The book is set in real underwater locations, and is illustrated with B&W stylised photos of the animals which live there, hence the choice to use a photo for the cover (I took the picture, so no copyright issues). Each book in the series will have an underwater photo from the appropriate location as its cover. This is intended for eBook publication. The cover is as close to finished as I can make it, so not just a concept test.

Nathan says:

Nice photo.

For a cover like this, which is essentially a background photo behind type, you really need typefaces that are going to carry the weight.  This typeface doesn’t.  I can see that you’re trying to convey a slightly antique, slightly fantastic mood with the type, but this typeface is too generic and overused (you also miss an opportunity to play with positioning between the initial caps and the rest of the words in the title).

Also, if “Pelagius Nemo” is the byline (and even I’m not 100% sure that it is), this might be an occasion where “A Novel by” is justified (or something more specific — “An Undersea Adventure by,” “A Saga of (and Under) the High Seas by,” etc.).

Other comments?

The designer says:

This book is a dystopian action, soft sci-fi. The target audience is adults age 19-30 or so. The book has LGBT+ themes, and later books in the series will contain somewhat less action and more political maneuvering as the story progresses, though action will still be present. The story primarily focuses on a violent rebel group that seeks to overthrow the repressive government. I am not the author, just a friend who is also not a professional designer. I did make this cover, however, and the author also agreed to changes based on your feedback.

Nathan says:

It’s a very eye-pleasing cover, although I’m not crazy about the typeface used for the series title, especially as it clashes with the other typeface used.

My bigger question is whether it communicates what you want it to about the story and setting.  It’s got a bit of that Hunger Games vibe, but that series isn’t the be-all end-all of dystopias; what can you do to communicate “dystopia” or “repressive government”?  Uneven paint in place of the smooth red background?  Rust and bolts on the dragon?  A militaristic stencil in place of one of the fonts?

I’ll let the others give more ideas.