In "", Asmodeus is described as one of the primal forces of evil in the D&D universe, and had a hand in creating Baator in order to punish sinners for their crimes. After being granted the power to do so, Asmodeus and his followers began consuming souls for power. Despite the horror of the good gods who'd established the Hells as a punishment, they didn't also expect its existence to help fuel evil in the world. As the devils consumed the essences of souls, they began to mutate into the devils that now populate the D&D universe.