Executioners are the creations of Luther Lansfeld and the Sphere Corporation designed to eliminate threats in the Eternal Sphere. They are sent to destroy the Milky Way Galaxy as it is considered "corrupt" after humans have advanced too far, manipulating genes with Symbological Power.
Three main types of Executioners appear:
Proclaimers: Executioners that resemble angels, these get their name because they proclaim the destruction of the galaxy. First appear at Moonbase.
Enforcers: Executioners that resemble large winged demons, these get their name because they enforce the will of the creator, annihilating the inhabitants of the Milky Way. Enforcers are shown to be incredibly powerful, easily overwhelming the fleets of the Pangalactic Federation, even destroying the battleship Aquaelie in a single blow.
Convictors: Executioners created by the use of Blair's failed shutdown program. Although smaller in stature, the Convictors are far more powerful than both Enforcers and Proclaimers.