Heather's real name is Cheryl Mason, the adopted daughter of the horror novelist Harry Mason, who survived Silent Hill. She is the biological daughter of Dahlia Gillespie, who is responsible for her original injuries. When Harry escaped Silent Hill, Alessa came back as an apparition and presented him with a newborn baby, which is both Cheryl, and Alessa herself, reborn. Harry, in an attempt to throw the cult off - should they come and look for both him and the child - renamed her Heather, and relocated to another city. When it comes to her personality traits within the game itself, one very obvious trait of Heather is that she is moody and loses her temper quite easily at things that frustrate her. She shows many examples of this behavior throughout the game.

Father Vincent is a priest of the The Order, but he takes a rather a typical stance on the subject of God. While he and Claudia Wolf both believe in God, they both have drastically different views on what God is, and if she can bring eternal paradise. For his part, Vincent is grounded in financial concerns and has no intention of creating any paradise. Throughout the game, the player must rely on Vincent's advice to reach the end. He urges Heather to go to Leonard Wolf and retrieve the Seal of Metatron, which he mistakenly believes will repel the God. He also provides a book which contains important information for defeating the game.

Claudia is a mysterious woman who appears frequently in Silent Hill 3, clad in black. While she is one of the key antagonists of the game, not much is revealed of her past. It is clear that she is a firm believer in the doctrine of The Order, and is trying to hasten the rebirth of God in order to create a paradise. Claudia is driven by the belief that a God born of pain and suffering is more likely to create a merciful paradise than a God that cannot comprehend empathy. The only clues concerning Claudia's past arise during a cutscene, where Vincent indicates that Claudia was abused by her father, Leonard Wolf. It can be speculated that her desire to create paradise is the product of an abusive childhood. As a child, Claudia was raised alongside Alessa Gilespie, Heather's original incarnation. As such, she sees Alessa as a sister and refers to Heather by her past name. Claudia's mission is to succeed where Dahla failed in the first Silent Hill, impregnating Heather with God and hastening its "birth". Claudia also holds a grudge against Harry Mason, the main protagonist from the first game who averted God's birth the first time. She hires Douglas Cartland to locate Heather, who went missing after Harry escaped Silent Hill 17 years prior. As Heather is drawn deeper into the Otherworld and tries to find her way home, Claudia dispatches the Missionary to murder Harry in their apartment and leave his corpse for Heather to find. Claudia then summons Heather to Silent Hill, and both Douglas and Heather follow.