Coven Compass

The Coven Compass (カヴン＝コンパス) is a Mobile Fortress, owned by Witches.

Appearance
The Coven Compass is a giant disk of stone 200m in diameter and 10m thick. The top of the disk has sharp lines running in each direction from the center, resembling an actual compass.

Principles
The fortress hovers about 20m above the ocean and has several countermeasures to prevent anti-flying spells from bringing it down.

On top of the fortress is a device designed to fire a large-scale flash spell which can be used to "fry" invaders.

English Civil War Arc
When the coup d'état was initiated, the Coven Compass, near Islay, was one of the many sites that were attacked by the knights and a battle ensued between them and the witches stationed on the fortress. The fortress was later used by the witches to launch an attack on Buckingham Palace.