The problem is that God is allegedly light (1 John 1:5).

Light is its own opposite (a photon’s anti-particle is identical to itself).

So there cannot be a Satan that’s the opposite of a God of light.

Also, the addition of Satan as a supernatural adversary in the Abrahamic tradition was probably the result of a later editor needing to change Anat petitioning El to kill the son of the protagonist as adapted from the earlier polytheistic Tale of Aqhat to set up the adapted dialogue of suffering from the Babylonian Theodicy into a monotheistic version and just replaced the goddess’ name with the generic term ‘adversary.’ So there’s the whole later fanfiction as just the result of a lazy editor adapting a polytheistic earlier story to a monotheistic version going against the whole ‘Satan’ thing too.