Play through a mission and finish it using actions to unlock either a "Good..." or "Evil..." trophy. Immediately after the mission success message appears, pause game play and choose to abandon the mission. Although you have to repeat that mission, the trophy that you earned will still be recorded. When the mission is replayed, use the opposite actions done in your first attempt to unlock the other trophy. By doing this, you will not have to repeat the enter game twice as good and evil.