and all the devils are here

Ominis Ciro Gaunt breathed his first as his mother exhaled her last. Delivered from the womb on the heels of Samhain twilight, the second son of the House of Gaunt came squalling into the world, feasting on the death rattle choking Medea Gaunt's throat. His father had named him appropriately enough.
Ominis.
A promise of something inauspicious, a lingering mark of something dark on the horizon. It was no wonder that necromancy called to him- he communed with these forgotten echoes, their rot-blackened fingers reaching for a taste of light and a voice to scream with, and responded with hunger. He'd been ravenous since the day he was born, and no food or water would quench it. No, Ominis Gaunt would only be sated by what the dead offered. Power.

An arranged marriage. A manor that does not stay the same after moonrise. A death-mage with blood on his hands and grave-dirt in his bones...and a bride who might not survive him.