The Solar is the highest rank in the Overchurch. He or she rules absolutely on all matters of religion. Secular kings and queens and emperors all bow down to the Solar, who represents the Torchbearer on Earth.
When a new Solar is elected by the Lanterns of the Overchurch, he or she participates in a holy ritual called Walking into the Flame. This burns away the candidate’s mortal coil and leaves only his spirit, which is merged with the Torchbearer’s. The new Solar steps out of the Flame a sort of ghost, purified of sin.
In this way, the Torchbearer can speak to her adherents. The Solar retains most of his or her original personality, but the Torchbearer’s will shines through. This allows the Solar to know directly the will of the Fire Gods and create religious policy that pleases them.