Paradox Bomb

The most powerful weapon in the Hyperion Federation arsenal.
The Paradox Bomb, when used, will destroy the entire universe by violating causality. It simply causes itself to destroy itself in the past, causing a paradox. The HF is extremely unlikely to ever use a Paradox Bomb as this would cause all within the universe - including the HF itself - to be annihilated. The HF does not store any techprints of a Paradox Bomb, even in the deepest most classified layers of their Grand Archive. If they do want to use it, they would need to create a techprint. They are also large enough to dwarf most skyscrapers in height. Considering that they are roughly spherical in shape they are easily visible from orbit. Furthermore it has delicate machinery inside so if shot the entire thing will be rendered useless until repaired. Additionally it requires energy to generate the wormhole used for time travel which can cause it to build up a huge energy signature, even if the bomb is not of HF origin.
Some other factions could possibly build something similar, but they too refuse to use it for similar reasons.