Who This Book Is For
Readers who love the concept of tech-meets-magic crafting and can overlook factual inaccuracies and flat female characters
Who This Book Is NOT For
Anyone with even basic metallurgy knowledge, readers who need well-developed female characters, or those who want romance rather than wish fulfillment
Our Review
The Setup
Pulled from 20th century tedium into a fantasy world threatened by monsters and evil wizards, our protagonist discovers he has magical power over earth and metal. In a world still swinging swords, he starts crafting armor, blades, and — most importantly — guns. The promise is irresistible: what happens when you drop industrial revolution technology into a medieval fantasy setting and give one man the magical ability to build it all?
Vall sets up a crafting-focused isekai harem with a premise that should be a home run. The fantasy of a modern man using superior knowledge and magical crafting to reshape a primitive world taps directly into the competence fantasy that drives this genre.
What Works
The premise itself is the selling point. The marriage of metalworking magic with modern engineering knowledge creates scenarios that no other harem fantasy on the market is delivering. When the MC forges his first firearm in a world that has never seen one, there is a genuine thrill of “this changes everything.” The crafting sequences, when they work, scratch the same itch as good base-building fiction.
The pacing is consistent. Vall keeps the story moving from one crafting milestone to the next, interspersed with action sequences where the MC deploys his creations against threats the world has never faced with this kind of firepower. For readers who enjoy the specific fantasy of overwhelming a medieval setting with technology, the book delivers on that promise at a structural level.
What Doesn’t
The factual errors are devastating for a book built on crafting and metallurgy. Steel does not come from purified iron alone. Quenching a sword in cold water is terrible metallurgy that would crack the blade. Horses do not kneel for mounting. These are not obscure details — they are basic facts that a single Google search would have corrected. For a book whose entire identity is “smart MC uses real-world knowledge,” getting that knowledge wrong is a fatal flaw.
Every woman in the story is unrealistically perfect and instantly infatuated with the MC. There is no courtship, no tension, no earning of attraction. Women appear, are described as impossibly beautiful, and immediately want the protagonist. In a genre that already struggles with flat female characters, Metal Mage sets the bar even lower. The sex scenes compound this problem with writing that reads as immature rather than explicit — the enthusiasm is there but the craft is not.
The world-building around the core premise is called pathetic by readers for good reason. The villain is ludicrously telegraphed, the climax is contrived, and the setting beyond the crafting mechanic has no texture. Everything that is not the forge feels like it was generated on autopilot.
The Heat
Spice level is a 3 out of 5. The explicit scenes are frequent and moderately graphic, but they suffer from immature execution. The writing reads like a first draft that never got a revision pass. If you need your harem books with polished, well-written intimate scenes, Metal Mage will feel amateur. The physical descriptions are there, but they lack the craft that separates good erotica from clumsy wish fulfillment.
Bottom Line
Metal Mage has one of the most interesting premises in the isekai harem space and does almost nothing to earn it. The concept of a metalworking mage introducing guns and industrial tech to a fantasy world is genuinely compelling — someone should write that book well. This is not that version. Between the factual errors that undermine the entire crafting premise, the cardboard female characters, and the immature writing, what you get is a rough draft of a much better book. Read it on Kindle Unlimited if the concept alone is enough to carry you, but do not expect execution that matches the ambition.
If You Liked This, Try
Both feature crafting-focused MCs in fantasy settings with harem elements and world-altering potential
Same author, similar civilization-building energy but with a crafting focus instead of god-simulation
Shared concept of a protagonist using unique economic or crafting abilities to reshape their world
The Verdict
Metal Mage has a genuinely unique premise -- merging industrial tech with fantasy magic through crafting -- but the execution is riddled with factual errors, immature writing, and women who exist as rewards rather than characters. The concept deserves better treatment than it gets here.