Realm of The Damned: Signum Draconis

It is the early 15th century and Athena struggles to defend her ancestral home from the predations of the Ottoman Empire. When she learns that House Petrova has struck a fateful pact with the Church of Rome, the pagan vampire commits the ultimate blasphemy. Desperate to save her land and driven by demons of her own, Athena forges a living weapon with which she will rout the enemies of Transylvania. But this is a weapon that cares for nothing but blood and butchery, and Athena may realise too late that she has started a fire that may consume both herself and the world.