This story first appeared in the AD&D supplement "Guide to Hell": Asmodeus is described as Ahriman, the twin brother of Jazirian the god of the couatls. In this story Jazirian and Ahriman were responsible for the establishment of the current arrangement of the planes but fought eventually because of their perspectives of the law (LG versus LE). Asmodeus is said to be a greater power without any need of worship in the guide. As the Forgotten Realms supplement Serpent Kingdoms, as well as the 2e supplement Monster Mythology, tells Jazirian is/was the lawful good aspect of the now-dead overpower the World Serpent, Asmodeus should be the lawful evil one. This interpretation puts Asmodeus as a more supreme evil than other equally official D&D canon, as he was in this material set up as the co-equal first cause of creation and the evil principle therein, rather than a reactionary segment and of evils potentially interpreted as lesser evil due to being meant to combat the demons of the abyss only having gone overboard, as in subsequent explanations of his origin.