Dire by S. B. Sebrick

In the epic conclusion to the 'Assassin's Rising' Series, a new Varadour Remnant emerges. Atacherous demands a contest of arms before the entire realm. Kaltor must prove his worth again, lest his followers be butchered for supporting him against the devious King.

He must also face the Venom Queen, Meriska, who specializes in untraceable poisons. Earning such a woman's respect challenges even the bravest of men, but she's also his fiancé's mother

But tearing aside one web of lies only reveals another tangle of deception. There's more to the meeting then a possible false Remnant. A great secret lies in the Citadel's depths, something even the Venom Queen herself could not keep hidden. Now demons and King alike turn their sole attentions to Keevan, the Sight Seeker Remnant, Kaltor's hidden brother.

His secret is out.

The earth itself will scream of war.