Still I am waiting for the certain faction cut from the game about the name black stalkers.
Article from Polish fandom stalker-
A model called "dark_stalker" exists in files of the game. It was supposed to be he placed from people which survived the other outburst in Chernobyl. The majority from these people didn't survive because of unknown illnesses and the rest was disfigured. They became half mutants and half people, weren't attacked by mutants and for some unknown reason could not leave the Zone. They knew a lot of secrets but didn't want to reveal none of them. She was their leader "living legend Stalker actually was Black Stalker he nondead about the nickname the Red. supposedly was supposed also to be a leader Raven. They worshipped the Black Bloodsucker which lived in Rostok before coming of the Duty. They weren't dark with hostility set but have often get stalker and brought him to Rostok in order to feed the Bloodsucker but if the one he went through it and survived they let him go or proposed attaching. After the appearance of the Duty they were Dark expelled and killed Bloodsucker (probably the same it is possible to meet the Bloodsucker in the Lost Alpha fashion. She is being called Bloodsucker there King).
This faction was removed just like The mutant-Ilusionist
Ilusionist Polish article: A Ilusionist is a mutant which was cut from the game by authors, before the formal premiere of the game. He was supposed to turn up at S.T.A.L.K.E.R. - Shadow of Chernobyl.
I hope you can add this it to the game :)
Polish STALKER fandom full articles