The Leviathan (also known as the Leviathanic Curse), is the malignant manifestation of a disembodied will belonging to a long-deceased individual. The will manifests as a web of vectors through which the scales of fate may be tilted in favor of a curse built on one condition:

Upon their death, the individual spoke a horrific promise. Their body was dying, and with it, the last flesh and blood of their people, now entirely driven to extinction by a vile genocide. They would not let their people be forgotten so easily by the world and their killers. Now knelt before the supposed friend who sold their people, their head moments from being severed, they spoke:

"You will stay your hand if you are wise. But I know you, and you will never heed. You are far too arrogant, and will never find simple peace in surrender. And with this, you begin your undoing.

Go then, watch what it means to win every battle and lose the war."