"How much the movie moved me... many of the scenes are painful to watch and really get your blood boiling."
Back in the 1980s there was a movie with Robert Deniro, and Jeremy Irons, IIRC, the Mission.
He played a Spanish count 1600s South America. When he kills his brother over a woman, he becomes a Franciscan and goes on a penitence mission into the Amazon dragging his armor and weapons behind him as a trial.
He becomes a great advocate of the natives, and essentially tries to lead the natives on a rebellion when the kings of Spain and Portugal divide the new world, and the Portugese, notorious slavers, get the land that will become Brazil.
Much of it was based on actual events.