Sin is an extremely hostile cult that was intended to appear in S.T.A.L.K.E.R.: Shadow of Chernobyl. They are hostile especially to the scientists, since they are competitors in searching the Zone for documents.
Described as zombified, Sin members are religious fanatics believing in the divine essence of the Zone and the redemption of mankind. They attack all stalkers on sight, apparently because they came under the control of psychic mutants.
They earned themselves the nickname "dark stalkers", owing to their dark green coats with hoods draped over their faces. If one lifts the hood on a dead stalker, he will see a bald head with a mutilated face.
- S.T.A.L.K.E.R.: Shadow of Chernobyl, Build 2205, gamedata\config\text\rus\string_table_enc_social.xml
- S.T.A.L.K.E.R.: Shadow of Chernobyl, Build 2205, gamedata\config\text\rus\string_table_enc_zone.xml Abandoned army base is there, an old village and a small lake. The grouping called Sin is now located within the army base… former religious zealots, who believed in the divine essence of the Zone, appear now to be under mutants control, although it still remains unclear. Once each member’s PDA has logged off since there has been no sign from them
- The Skin for Trenchcoat wearing bandits refers to them as "Dark Stalker", making them a possible carryover from the cut faction. There's a green version of the Trenchcoat located in Shadow of Chernobyl files, named "act_ds.dds". the "ds" possibly mean Dark Stalker.