The Dark Lord's Guide to Marriage (and Other Ritual Sacrifices)

The Dark Lord and Lady are at war with an ancient evil, a guild of backstabbing villains, and the entire demon realm—so basically, the marriage is thriving—in this wickedly funny and scorching third book in the Guides to Villainy and Love series that is Assistant to the Villain meets Dreadful.
Step Seven: Destroy the ancient evil you set free.
Step Eight: Cross every enemy off your list (permanently).
Step Nine: Try not to lose your wife to the power she craves.
The honeymoon is over. The apocalypse has arrived. (And they’re technically responsible for it.) Dark Lord Kazimir Blackrose has a list of problems longer than his list of enemies, which is saying something. The Shadow King he freed to save his wife is amassing power the realms haven’t seen in two thousand years, the Syndicate wants his head on a decorative pike, and the demon realm wants the rest of him delivered alive. Worst of all, his beloved wife’s magic is changing into something even he can’t protect her from.
Arabella Blackrose isn’t afraid of her darkness—she’s rather fond of it actually. But between hunting Syndicate Chairs and shocking revelations about her bloodline, she’s discovering that power always collects its debts. And this time, the price might be her.
Now the realm’s most dangerous couple must do the unthinkable: sacrifice everything they’ve built to destroy an evil older than the kingdoms. Villains are supposed to conquer the world. They’re certainly not supposed to save it. But no one has ever accused the Blackroses of doing things properly.
This deliciously dark and sizzling fantasy romance is perfect for readers who love: villains who stay gloriously villainous (and disgustingly in love); a heroine embracing her dark side no matter the cost; touch her and die energy; found family of villains, a hero, and one judgmental dragon; wickedly sharp banter and blistering spice; and a happily ever after with a body count.