The Seven Sisters of Purgatory (煉獄の七姉妹 Rengoku no nanashimai), also known as the Sisters of Purgatory, the Stakes are weapons used by Beatrice. They can bounce off walls and objects to attack from any direction and it is impossible to escape them unless the victim has strong magical resistance. They can transform into human form where they use blades of light to attack their enemies.
Following Beatrice's defeat in End of the Golden Witch, they become furniture to Battler. After Beatrice's defeat and their capture, it is revealed by Bernkastel and Erika that their vessels are cheap fake occult stakes "Made in the USA" that Kinzo was tricked into believing were real.
There are seven Stakes of Purgatory, each named after a demon representing one of the Seven Deadly Sins. They include the following characters.
- Lucifer of Pride
- Leviathan of Envy
- Satan of Wrath
- Belphegor of Sloth
- Mammon of Greed
- Beelzebub of Gluttony
- Asmodeus of Lust
All of the sisters have the same powers. They use swords of light in battles and often turn into stakes and pierce their victims until they die.
The Stakes of Purgatory fought against several characters in the series. They usually won, but lost twice.
The Seven Sisters have two theme songs:
- Nanairo no Niji Kakeyou
- The lower half of the Stakes of Purgatory's attire is extremely similar to the Angel Mort restaurant uniform from Higurashi no Naku Koro ni.
- The Stakes of Purgatory's relative ages directly correspond to the order of the terraces in Purgatorio as Dante and Virgil ascend towards the meeting with Beatrice - pride first, lust last.
- All of the Stakes are modeled after servants Yasu has met during his/her time as a servant.
- Even though being grouped together, it should be noted that the stakes will act independently of one another, and sometimes don't acknowledge each other, even in the heat of battle. However, in the end, the stakes will always be willing to work together to bring down a common foe, or fail to skewer something.