To me its a deeply spiritual question. Is the person genuinely repentant on their actions? Are they willing to take responsibility for what that entails?

I've been recently watching the Dragon Quest Dai anime where the concept of face turns are fundamental to the plot and themes and are done rather matter of factly. One of the characters special moves post turn is literally BEAST KING REDEMTION BLAST The idea that the situation at hand is actually morally complex and that peoples goals cant often be simplified as wholly evil or good is an important point because its truly a matter of perspective especially in war.

The world is set up by the gods so that humans can enjoy the surface world and do whatever the want oppressing monsters (who are sapient and many of which can speak) and fighting darklings (dark elves who arent inherently evil) for glory and go to heaven. While monsters dont have rights and most of them are forced to live in hell and no matter how virtuous they are none of them will be graced by god and sent to heaven. So the non humans stand up and say they should also have a right to the sun and surface world and begin to attack humanity. In this situation many of the foes the party faces are people with genuine grievances with them including one who held a grudge against the previous Hero for killing his father who was a monster.