This is a world ravaged by a cataclysm, where morality has collapsed and humanity is on the brink of ruin.
Evil thoughts breed evil deeds and corrupt the ley lines. The Temple arose to oppose the Demon Tree.
Luciel, whose soul is the purest of all, takes up the bishop's mantle and becomes a Poet.
His quill can purify all sin, but the price is the burning of his own soul.
Aloit, commander of the Temple Knights, guards him as he walks the last road to victory.
Temple's treasure: frail, sickly Poet Luciel, the receiver × loyal, protective knight commander Aloit, the giver.
My own take on Western fantasy. Poets are a profession, and their power is purification.
The same goes for other roles, such as knights and painters.
Theme: Ideals never die.