Short answers, pulled from the story.
Heather Mason is the reincarnation of Alessa Gillespie, a girl whose immolation thirty-eight years earlier created the town's shifting dimensions. She is the only way to free her mother Rose Da Silva who remains trapped within the town's Otherworld.
The Order of Valtiel is a cult of Silent Hill that orchestrated the burning of Alessa Gillespie to birth a deity that would punish all sinners. Claudia Wolf serves as the priestess of the Order and seeks to use Heather as the vessel to bring the god into the world.
The Missionary monster was created by video game artist Masahiro Ito for the 2012 film Silent Hill: Revelation. This creature emerges when the Seal of Metatron is touched and serves as a grotesque manifestation of Claudia Wolf's true form.
Vincent Cooper betrays Heather Mason because he is the son of Claudia Wolf and a member of the Order of Valtiel sent to ensure that Heather comes to Silent Hill of her own volition. He is ultimately taken away by the Order after being deemed insane by Claudia for betraying them.
M. J. Bassett expressed regret over the film's production and admitted that she felt obligated to claim it was a great movie for the press. She apologized to everyone who did not like the movie and wished she had stood up for her vision of the movie and for the fans.
Silent Hill: Revelation had a total gross of $55,975,672 worldwide. The film received largely negative reviews from critics and its box office performance was modest.