One method is through a series of increasingly intense provocations.
The function of those provocations is to incrementally reverse the character.
In THE GODFATHER (1972), Michael undergoes a series of increasingly intense provocations, which gradually change him.
So that the hero is a different creature in the end to what he is in the beginning.
That, however, is a linear reversal. Commonly, the provocations (and therefore reversals) are stage-gated between other processes.
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