Liberator

Liberators, also called Planet Killers, are the most powerful Red Lantern weapons, capable of destroying entire planets when implanted. They were used by the Red Lantern Corps in their single-minded campaign against the Guardians of the Universe and the Green Lantern Corps. The Planet Killers are equipped under Shard  and can be launched down from the planetoid.

One was used to obliterate Colony 12, another was implanted on Betrassus, but this failed. A few were implanted into the Maelstrom and blew a giant hole through it. Some were going to be used to destroy a giant invading robot, but they were destroyed.

History
Atrocitus used a Liberator on Colony 12, threatening that it would destroy them and their homeworld unless they gave the Green Lanterns Hal Jordan and Kilowog to him. Even though with the interference of the Green Lanterns on Colony 12, the bomb still succeeded to destroy the planet and Green Lantern Shyir Rev, but the citizens survived.

Another Planet Killer was implanted on Betrassus. Though before it could detonate the Green Lanterns Hal, Kilowog and Ioland used their new-found boost in their Power Rings from an unknown source to lift off the Planter Killer out of Orbit and saved Betrassus.

A few blew a hole through the asteroid blockade seperating the Forgotten Zone and the Green Lantern side of it. During the Red Lantern invasion into Guardian Space, Shard came into battle against Kilowog, Saint Walker and Mogo who could destroy the Red Lantern armada. Shard launched several Planet Killers towards Mogo in order to obliterate it. However they were immobilized by the combined Power Rings and strength of Mogo and Saint Walker, preventing the Red Lanterns from entering into Guardian Space.

It's presumed that they were all destroyed by the Anti-Monitor when it obliterated Shard. They might still be produced, but this is unlikely, as the Red Lanterns now assist the Green Lanterns.

Capabilities
A Liberator, despite it's name, is able to destroy an entire planet  and blew a hole through the Maelstrom. Due to their size and their tough substance, it's seemingly impossible that it can be destroyed, except with a powerful attack. They also are hard to difuse, seeing as it was hopeless for Shyir Rev. A Planet Killer is also equiped with a large hologram projector, to let Atrocitus demand his desires on a certain planet.

It's unknown if Anti-Monitor is vulnerable to Liberators.

Design
A Liberator is large, and has a cylinder shape. The inside of the Liberator has a lot of space, making the Liberator also to be used a foretress. It can spread out spider-like claws, to put itself in place. It seems to run on plutonium.