I'd like to run a game as Katrina and Abraham. I think the dynamic is fascinating and has a lot of intentional. For those who don't watch the show-Abraham is the Horseman of Death who has always loved Katrina. She however loves another and chose Crane over Abraham.
Abraham died in the revolutionary war, killed by the very man who stole his love, Katrina. Centuries pass before he is reborn, as the Horseman of death. He is charged to bring about the end of the world, using magic, demons and human allies to do so. Things seem to be going well when Katrina is resurrected to fight him.
She belongs to an ancient order of witches. Abraham, burning with desire, captures her and imprisons her. He lost her once, he will not lose her again. Whatever it takes, he will have her.