Dart is a young boy, growing up in a quaint native village, and his life is about to change forever. We generally always assume that a protagonist's life is going to change forever, so this needs to be more specific. What is he changing from? What causes it? This is a good place to show some character - "Dart is a headstrong shepherd boy with dreams of being a fire-eater"
When a fire claims his home and his father, the villagers are forced beneath the surface What surface? Is there an underground complex already in place?. There they form a resistance against the conquering race known as the Adelians. So was the fire on purpose? The wording doesn't connect any of these instances. I would suggest something like "When the Adelians attack Dart's home and kill his father, the remaining villagers retreat underground to the nuclear bunkers (or whatever) to form a resistance against the enemy"
Years pass, Dart grows, and so do his abilities. For he is a prophet—an extension of the mighty sun goddess, Aris Above, and he can drawn energy from her rays. Not until he crosses paths with a brilliant, yet self-absorbed, scholar that he realizes the potential of his power. THIS is where it sounds like your story actually begins.
But that scholar, an Adelian named Parzei Bronzefield, is a kingdom away. So how they did meet? What connects them? And she is busy deciphering an ancient formula inscribed in a cryptic shorthand. A formula her superiors think is a recipe for fuel, but in reality
it's is much, much worse. For it's part of an ancient religion, a prayer, a gateway. All three? The key to releasing an imprisoned god. And an entity—a prophet of a different kind of faith, one of ancient alchemy—will stop at nothing to get it.
I am a software engineer with a physics background. Coming from a science background, I enjoy when it accompanies world-building. I believe you'll see that in TRANQUILITY, a fantasy novel with a series potential complete at 100,000 words.
I don't get who is the protagonist here, Dart or Parzei, or how they're connected. I assume Dart is the prophet of a different faith, but why will he stop at nothing to get the formula? The formula summons a god, but then what? What actually happens in the plot? What are the stakes here? What do Dart and Parzei have to lose and to gain?
I know it's difficult to be specific because you don't want to be spoilery, but you really need more specificity here. As I understand it, the main story is that Parzei has a formula and Dart wants it. But what personal journeys are they going on? What character arcs are happening? If you can give a hint of what those are, you'll have a much more enticing query.