Annihilatrix

The Annihilatrix was the name the Dogs of War used for a device built by the modrons that was a sort of powerful magical bomb. It consisted of four conduits which divert energy from the four elemental planes into a central chamber which focused the energy and would create a massive explosion of energy when activated. It was built apparently to destroy the city of Sigil. It was captured intact by the Dogs of War who modified it and used it to destroy the modron Primus and free the Lady of Pain.