Solasta: Crown of the Magister

Have one of your party with the Philosopher background and play through the background side quest that will trigger part way through the game.

Philosopher is a weird background, as its parts are less than its whole. Persuasion is okay. And Medicine or Herbalism are fine, but they don't stack. You also get two extra languages. I would not pick Philosopher for any reason except to get the achievement. The quest is time-consuming, but easy. This one is unlocked after Gem Quest: The Monastery. Talk to the mayor in the center of the circle. She sends you to Galeafin near the tavern. He'll talk for a while about the nature of evil. Go rest at your house in the place until he calls for you again. Repeat. You'll meet Illoreth, a member of the evil god cult. The two of them want you to infiltrate the cult and kill the Sorak in charge, which is pretty easy. Meet Galeafin again, and he'll leave town with Illoreth. You'll earn the achievement.