- Complete each achievement associated with the Speaker's Black Sacrament contracts.
Flawless Sacrament is awarded for completing each of the achievements associated with the Dark Brotherhood's Black Sacrament quests. These include:
- Blackest Sacrament — There are 21 targets you must assassinate for this achievement.
- Hidden Sacrament — You must complete at least one of these assassinations without being detected.
- Perfect Sacrament — You must complete all of the optional tasks for at least five of these assassinations.