Hi! I'm jumping in here at draft 11, and didn't want to read earlier versions because I wanted to come to it fresh. Also, this is my first critique!
Seventeen-year-old Norvina doesn’t look dangerous. Definitely not someone you'd expect to slaughter a squad of super-villains with just fire and a stick at her disposal. [I like this hook. It's quick and to the point, and tells me where my sympathies should lie.]
In NYC [why not New York City, spelled out? Seems too casual.] super-villains are respected citizens, but they have seniority [I'm not sure "seniority" is the right word, or what it means in this context]. To differentiate themselves from the citizens, they wear black suits and a red tinted metallic skull mask. [Do you need this detail? It doesn't seem to impact the story, and I feel like it slows things down. The main point is that super-villains are respected citizens, right?] The city is governed by the Mayor, Black Death, ever since he annihilated all superheroes. He has one law: all humans with superpowers that don't side with him must die. Which is bad for Norvina because she just got them in a big way.
[I found jumping to this paragraph a little choppy--I was a little thrown by the leap from Norvina to NYC, but that might be effective because of the brevity. I know agents don't have a lot of time to read queries. So take my comment with a grain of salt. But I will say, you might want to play with the order of your sentences here. It might be more economical to lead with the fact that NYC is governed by Black Death, then go into how super-villains are respected citizens; and then close, as you have, with his one law, which holds all the punch.]
When Norvina is attacked in an alley by thieves, her adrenaline triggers a mutation in her DNA that gives her power over fire. She roasts the muggers and draws the attention of super-predators. Overpowered by the bloodthirsty freaks,[Not sure you need this opening phrase. Try cutting it, and see if it matters.] Norvina is saved at the last second by a young man named Vulcan—who's ruthless and on the run from his own father, Black Death. Ever since Vulcan refused to be a super-villain, his father placed a hit on him. [The wording of the previous sentence bugged me a little. Maybe: "When Vulcan refused to be a super-villain, his father placed a hit on him."] He agrees to train Norvina in the art of fire [I don't know what the "art of fire" is. Maybe find a way to clarify it concisely.] with his own power of light manipulation if she helps kill his father. Norvina, desperate to survive, [Nitpick: I'd remove the previous comma because it slows things down.] though still mistrustful of Vulcan, accepts when she sees the hatred he bears for his father.
With law enforcement and flesh-feeding villains attacking her at every turn, Norvina soon learns more about the harsh truth ["harsh truth" suggests more of a general state, like "dog eat dog," than a single plot. I've suggested alternate wording in the revision of the graph below.] of the world she’s trapped in—she discovers the plot between Black Death and the government. They plan to mobilize an army of super-villains to take over more than just the city—the potential army would threaten millions of lives, including her own. Norvina must do the unexpected—she herself will have to become a villain to survive.
[This paragraph felt a bit overloaded. Here's a whack at a revision. Take it or leave it, as seems appropriate: "With law enforcement and flesh-feeding villains attacking her at every turn, Norvina learns a terrifying fact: Black Death and the government plan to mobilize an army of super-villains to take over more than just the city. Millions of lives hang in the balance. Norvina realizes she must do the unexpected: She will have to become a villain to survive."]
I hope this is helpful! I think you have a really strong query--it provides a clear picture of the stakes of your story and the world you've created. My edits are really just suggestions toward polish. Good luck!!!