They are both arts of lititure and both have the same purpose
The role of a foil in a literary work to to provide contrast against the protagonist, in order to further highlight one or more characteristics of the protagonist.
Answer:
The ending did support the fakirs belief. At the end the White's most beloved thing (their son) was turned into a horrible monstrosity from the dead. This happened because the Whites wished for their son back from the dead. Upon this wish they tried to play God and messed with fate.
Explanation: