The Epilogue

The most devastating fleetkiller type Weapon of Mass Destruction in existence, as most of the 'most something' supertechnologies being a voidtech. There are merely four in existence, all of them considered an asset that is beyond valuable. They can be safely considered an apex of this particular subtype of weaponry.
The Epilogue name pretty much seems up the way it works. When finally loaded it seems to create a short lived and limited in size alternate dimension centered on the chosen point. Said dimension seems to temporary overwrite the real one... but then it suffers what can be summed up to a vastly sped up Big Crunch, being crushed to a level of superheated and ultradense quark matter and then dispersed as the dimension collapses, in what is pretty much an apocalyptic event on its own.
Being caught in the Epilogue's salvo is equal to an almost guranteed death. They have been a singular cases of ships escaping via a Void Drive. Other than that, the death is sure and unavoidable. There is a brief period before the weapon is launched that its area of effect is already known, but it can still be exited... but the size of it means that escaping it in time is rather unlikely.