The Assassin, the Conqueror, and the Vow Between Them

Some books in a shared universe exist to fill gaps. Slaying the Vampire Conqueror is not one of them.

This full-length standalone sits entirely outside the main Crowns of Nyaxia storyline, in the mortal kingdom of Glaea, and it tells a story that owes nothing to Oraya, Raihn, or Mische. If you've never read a page of this series, you can start here and lose nothing. If you've read all of it, this deepens the world in ways the main sequence doesn't have room for.

Either way, it's excellent, and it's the entry most readers skip.

What It's About

Sylina is a Sister of the goddess Acaeja, bound by vows, trained as a weapon, and dispatched on a mission that requires her to become something she's spent her life refusing to be. She is to infiltrate the army of Atrius, the vampire warlord carving a bloody path across Glaea, earn his confidence, and put a blade through him.

She becomes his seer instead.

Atrius is not what the reports describe. He is ruthless, yes, and the bodies behind him are real. But he is also a man carrying a past that Sylina recognizes with uncomfortable precision: the specific damage of someone who was made into a weapon before they were old enough to consent. The more she sees of him, the harder it becomes to reconcile the target with the person.

Meanwhile, the blood spilled by Glaea's tyrant king keeps rising, and Sylina's orders remain what they were. The conqueror cannot live.

Why It Works

The seer conceit is the smartest structural choice Broadbent has made in this world. Sylina's role requires her to be physically close to Atrius, constantly, in a position of intimate access, and every moment of that proximity is a moment she's supposed to be using to plan his death. The tension isn't manufactured. It's built into the job.

Atrius is arguably the best-drawn male lead in the Nyaxia world. He isn't a brooding king or a charming rogue. He's a soldier who has organized his entire existence around competence because feeling anything else was never an option. His slow recognition that Sylina sees him (actually sees him, past the conqueror and the reputation) is rendered with restraint that makes it land harder than a dozen declarations would.

The forbidden element here is genuinely forbidden. Sylina's vows aren't a social inconvenience; they're the structure of her identity and her connection to her goddess. Breaking them costs something concrete. Broadbent understands that "forbidden romance" only works when the prohibition has teeth.

Where It Struggles

The setting (Glaea, the mortal kingdoms, Acaeja's order) requires substantial worldbuilding that eats into the first quarter. Readers coming from the main series will find themselves relearning a cosmology they thought they understood.

The supporting cast is thin. Atrius's army and Sylina's order both function more as context than as populated communities, which makes the middle sections feel occasionally airless. This is a two-hander, and when the two aren't in a room together the energy drops.

The ending resolves its central impossibility somewhat more smoothly than the setup earns. Broadbent writes herself into a genuinely difficult corner and finds a way out that works but doesn't quite cost what it should.

The Velvet Coven Verdict

Slaying the Vampire Conqueror is the most underrated book in the Crowns of Nyaxia world. It's self-contained, it's tightly focused, and Sylina and Atrius have a slow-burn dynamic that rivals anything in the main sequence.

It's also the perfect recommendation for the reader who says they're curious about this series but intimidated by a five-book commitment. Hand them this. If Atrius doesn't work on them, nothing in Nyaxia will.

Read it whenever. That's the point of a standalone.

Quick Reference

  • Author: Carissa Broadbent
  • Published: 2023 (standalone, full-length)
  • Series: Crowns of Nyaxia, standalone (read at any point)
  • Setting: Glaea, mortal kingdoms, Atrius's war camp
  • Tropes: Assassin, enemies to lovers, forced proximity, forbidden vows, morally grey hero, slow burn
  • Spice level: 4/5: explicit
  • Status: Crowns of Nyaxia standalone, Tor Bramble edition