The Great Law of Blood is simple: when you kill someone, you take their EXP. When you get enough EXP, you level up. When you level up, you become better at killing people. The cycle has continued since before the time of the gods and has been going on thousands of years after they died. It's a good thing, of course. It rewards punishing the evil creatures of the world: goblins, kobolds and other sorts of terrible monsters. It will surely go on for eternity.

People thought the gods would live for eternity too, but they were slain. This world has never, and will never, stand still.