When we meet Harrow in episode one, he's located in a remote European village where the people worship him. He says he serves the goddess Ammit and judges others in her name using his magical scales tattoo. If the tattoo judges someone as bad, they spontaneously drop dead.
Harrow later tells Steven that Ammit is tired of waiting for people to do something bad to judge them, and she wanted to get rid of people before they committed crimes. Harrow says Ammit would have stopped dictators from rising and genocide from happening. Harrow says she was betrayed by "indolent fellow gods" and her own avatar. How Harrow found out about Ammit and ended up on the road to try to free her hasn't been explained yet.
In the real world, Ammit was a beast in Egyptian mythology who's associated with the end of the world. If someone's heart did not balance the scales of truth, she devoured them.
