A baby is born in Apartment 302 of the South Ashfield Heights apartment building. He is abandoned at birth by his parents and found by the superintendent, Frank Sunderland. The baby is then sent to St. Jerome's hospital where he stays for a short while.
The baby is declared a ward of the state and taken in by the Wish House Orphanage in Silent Hill. He is given the name Walter Sullivan.
At six years old, Walter is taught to read and write. A High Priestess, Dahlia Gillespie, told him that his mother was 'asleep' at the place he was born. If he read the 21 Sacraments for the Descent of the Holy Mother well, then he could meet her.
Walter made the journey to South Ashfield Heights repeatedly as a child, attempting to meet his mother. He would try to glimpse into Apartment 302 and slip letters under the door, asking 'why [his mother] wouldn't wake up'. The tenants living in the neighbouring apartments saw Walter as a pest and began to treat him badly when they saw him around. Eventually, after many attempts, he abruptly stops trying to visit the apartment.
Valtiel, an 'angel' who oversees the cult's God, was 'secretly' slipped into Walter's subconscious by Jimmy Stone and George Rosten, the priests who ran the Wish House orphanage. This may have given him supernatural abilities.
Throughout his childhood Walter was heavily abused and tormented, through psychological manipulation, physical beatings and isolation. He would be beaten for wandering too far from the Wish House.
For misbehaving or 'to please God', he would be sent to a prison cell where the gaurds would frequently abuse the children in their care. One gaurd, Andrew DeSalvo, forced him to drink water with leeches in.
He had a friend once, a fellow orphan named Bob. Bob vanished in Walter's youth; Walter believed DeSalvo was responsible.
Headcanon
Through further abuse, the other orphans were taught to stay away from Walter, isolating him from them.
Walter was around ten years old when Valtiel was placed within his mind.
Valtiel would infrequently show Walter the Otherworld. Walter mistook this as Valtiel showing him what the world was truly like.
Walter was taught how to dance as part of ritual ceremonies to worship and give praise to the sun. This became a hobby of his.
While Walter has a deep hatred for bats and moths he actually loves birds, especially corvids like ravens.
Childhood
Canon