The Requiem Blaster is a powerful weapon of the Thirteen that is able to draw power from a quasar's sound waves, a supernova's thermal energy, or a black hole's gravity. The blaster is massive enough to have its own gravity and is far too large for a modern Transformer to wield or even pull the trigger.
The Requiem Blaster was reluctantly created by weaponsmith Solus Prime, at Megatronus's urging during the battle against Unicron. Possessed of great power, the Blaster was capable of leveling mountains. The Thirteen decided by a vote of seven to six to allow the weapon to exist. At some unknown point, the Requiem Blaster was placed on a ship which was lost in deep space. Yet so great was the gravity of the mighty weapon that over many eons, it caused countless pieces of junk drifting in space to collect around it, eventually making it the gravitational center of Junkion. Much later, Megatron found this weapon and attempted to destroy Optimus Prime with it, but he survived. The removal of the Requiem Blaster from Junkion caused the artificial planetoid to fall apart. The Decepticons had to eject the weapon out of the Nemesis due to it overheating, and out of the very real fear of it could explode. It would later become a target for the Star Seekers to find in their quest to destroy Cybertronians.
The weapon later came into possession of the Star Seekers at last, and was mounted on the Tidal Wave, the ship of their captain Thundertron. Encountering Megatron and the Nemesis crew utilizing the weapon as a death threat, Thundertron remained unaware of the overheating qualities and vast amounts of energy needed to power the weapon, something the Decepticon leader knew about all too well. The Star Seeker captain boasted of how he destroyed the Autobots with the Requiem Blaster, which Megatron briefly considered a possibility before taunting Thundertron. The Star Seeker leader replied by using the Requiem Blaster on the Nemesis, first blasting through an asteroid obstructing their line of sight. However, their second attempt resulted in a significantly weaker blast and the inevitable overheating of the weapon, and the Tidal Wave ultimately jettisoned the Requiem Blaster to ensure the crew's safety.
It's current whereabouts are unknown.