Who is Antonio from A Tempest: Based on Shakespeare's The Tempest, Adaptation for a Black Theatre and what is their importance?

Propero's brother, Antonio, usurps his brother's position and is directly involved in the conspiracy to denounce his brother to the Holy Inquisition for sorcery. After being shipwrecked on the Island where Prospero, he repents of his crimes against his brother, earning Prospero's forgiveness.