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.
Executed a total of 1000 witches and enemies.
Purified Princess Poeme.
Defeated Harina.
Acquired the Frailty Incense.
Abandoned your mission in favor of the witches.
Collected all the archives.
Purified the witch deity Parushee.
Purified the Witch of Lust.
Collected a total of 20 silver coins.
Defeated Frikka, leader of the thieves.
Purified the witch deity Saora.
Warmed up Almu, the slug girl.
Purified Sister Devoir.
Rescued Princess Amelia from a group of witches.