In the far-reaches of space, there drifts a colossal unmanned manufactory, shaped like a sword.
None know the true origins of the vessel, but many believe that some ancient alien race built the factory to act as judge and jury for a neighboring planet. The ship houses an impartial A.I. that judges the actions of any sentient life-forms it encounters. Then, if it senses any impropriety, it dispenses its executioners. Automatons are built to severely punish those who the ship deems reprehensible. However, the A.I. is inordinately harsh in its rulings. So much, in fact, that many think this spelled the fate of the original creators of the A.I.
The Celestial Tribunal has acted thusly for millenia. If it finds its way into your galaxy, be prepared for a harsh sentence.