Is it forbidden to believe the fatwas of a sheikh who was later discovered to be a sorcerer, knowing that these fatwas did not touch upon the knowledge of the unseen?

It is permissible to believe in juristic fatwas from someone who was thought to be righteous, as long as they do not contradict the Sharia, especially before knowing that he uses magic. He may have a degree of goodness, as happened with Satan and Abu Hurairah. As for believing a magician or soothsayer in what he claims about the knowledge of the unseen, it is disbelief in what was revealed to Muhammad, peace be upon him, because of the Almighty's saying: "Say, 'None in the heavens and earth knows the unseen except Allah.'" However, believing him in matters of jurisprudence and worldly affairs does not fall under this. Nevertheless, a fasiq (transgressor) should not be consulted for fatwas, because justice is a condition for the one who is consulted, and magic is one of the grave sins.