Achilles: Legends Untold

Each time you face a human boss enemy in the game, after depleting their health bar you will get a choice. To the left is the option to kill the boss and to the right is the option to spare their life. You will usually get a weapon or shield when killing a boss and a new skill when sparing them. You have ten seconds to make the choice and can either let the time run out or press  to confirm your choice. For this achievement, be sure to spare every boss in the game. You will also unlock Fate of a hero (15G) at the end of the game for doing this as well.