What is the truth behind what is rumored about sorcerers who appear in the form of embers or birds and absorb human blood from a distance, and how are they dealt with?

Linguistically, sihr (magic) is that whose cause is hidden. Technically, it cannot be confined due to its many types. It is a science that has a reality and an effect, and some of it is mere illusion. Its effect may reach the point of separating spouses and causing illness. Magic is not permitted, nor can it perform miracles. There is a difference of opinion regarding the permissibility of a human transforming into an animal, or a sorcerer flying or walking on water through magic; some scholars have permitted it. What the questioner mentions may be illusory magic or real magic if it is said that the sorcerer transformed into a bird. Sheikh Al-Alawi mentioned in Rushd al-Ghafil what is known as al-mass (possession) or al-sall (consumption/wasting) and its cure.