Jacob's nemesis, the man in black, is Randall Flagg.
Firstly, in the closing paragraph of "the Stand"
... Flagg reappeared somewhere on a beach and gained a new group of individuals to control.
Secondly, some of Randall Flagg's powers are:
Flagg is described as "an accomplished sorcerer and a devoted servant of the Outer Dark"[3] with general supernatural abilities involving necromancy, prophecy, and unnatural influence over predatory animal and human behavior.
It has been eluded in the show that the man in black had taken over certain important characters' bodies/memories. Also, it is believed that Smokie is controlled by him. These characteristic would be consistent with Randall Flagg.
Firstly, in the closing paragraph of "the Stand"
... Flagg reappeared somewhere on a beach and gained a new group of individuals to control.
Secondly, some of Randall Flagg's powers are:
Flagg is described as "an accomplished sorcerer and a devoted servant of the Outer Dark"[3] with general supernatural abilities involving necromancy, prophecy, and unnatural influence over predatory animal and human behavior.
It has been eluded in the show that the man in black had taken over certain important characters' bodies/memories. Also, it is believed that Smokie is controlled by him. These characteristic would be consistent with Randall Flagg.
