Here is the full list of all 8 审判者 The Inquisitor achievements.
Make your first trial.
Learning the truth ... to some extent.
Lambert gets the punishment in Dusted Tavern.
Finish the quest from Alfred.
Defeat Ipsum less than 10 skills equipped.
Defeat Ipsum with the skill "Reality".
Defeat the Deep-sky Hell's Guardian without using purple skills.
Finish the battle with two sinners in the easternmost of Hell within 5 turns.