Here is the full list of all 15 Minoria achievements. It takes around 6-8 hours to unlock all of the achievements on Windows.
Defeated a major enemy without taking a hit.
Purified Princess Poeme.
Acquired the Frailty Incense.
Defeated Harina.
Collected all the archives.
Abandoned your mission in favor of the witches.
Purified the witch deity Parushee.
Purified the Witch of Lust.
Collected a total of 20 silver coins.
Executed a total of 1000 witches and enemies.
Defeated Frikka, leader of the thieves.
Warmed up Almu, the slug girl.
Purified the witch deity Saora.
Purified Sister Devoir.
Rescued Princess Amelia from a group of witches.