Requiem Blaster (Megatronus)

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 former archivist Optimus Prime has never encountered any record of a Transformer surviving a direct hit from the Requiem Blaster. It might just be the most powerful weapon ever.

Aligned novels
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. Its current whereabouts are unknown.

Prime Wars Trilogy cartoons
Long ago, the Requiem Blaster was forged by Solus Prime to defeat Unicron, with Megatronus using it to finally destroy him once and for all. Fearing what would happen if its power fell into the wrong hands, Solus believed the weapon was no longer needed and should be destroyed. Megatronus refused, believing he should maintain custody of the it. The two fought over the blaster, but it was accidentally discharged in the scuffle, killing Solus. To prevent another misuse, the remainder of the Thirteen took back the blaster and sealed it in a dome in Primal Swamp, tasking a line of bots with righteous hearts to watch over it that culminated in Optimus Primal.

Many years later, the whereabouts of the Requiem Blaster had been lost to time. During Trypticon's assault, Optimus Prime received visions of the future from the Matrix of Leadership, including one of the Blaster united with the Matrix and the Enigma of Combination, though he knew not its meaning. Some time later, having already obtained the Matrix and Enigma, Megatronus began searching for the Blaster, hoping to unite the three artifacts to create a weapon that could drain the spark from every Transformer, the energy of which would be enough to bring back Solus. Megatron also led a team to search for the Blaster, using the Book of the Second Prophecies to determine that it was likely somewhere in Primal Swamp. Discovering a dome hidden in the swamp, he investigated and found the gun waiting inside, thought he also came face to face with Optimus Primal, who had been guarding the gun since before he could remember. The two fought briefly, but sensing his resolve, Primal surrendered the gun to Megatron, who eventually emerged with the Requiem Blaster in hand and used it to threaten an enraged Predaking.

The team later found the hidden location of the Athenaeum Sanctorum, where an information terminal explained what had happened to the Requiem Blaster in the intervening years. The arrival of Overlord and Rodimus Cron led to a long fight, with Perceptor briefly threatening Overlord with the Blaster before dropping it as Rodimus threw Megatron into him. Primal grabbed the gun and attempted to flee the Sanctorum, but ultimately hid in the shadows until the opportunity presented itself, at which point he tossed the Blaster to Megatron, who fired it at Overlord. The blast took out both Overlord and a sizable chunk of Cybertron, but their victory was short lived as Megatronus sensed the blast and appeared to take it away. A struggle ensued, culminating in Megatronus knocking everyone aside and grabbing the gun before blasting off into the sky with it.

Returning to the Well of Sparks, Megatronus installed the Blaster into his doomsday weapon and began siphoning the life force from every Transformer's spark. Perceptor attempted to remove the Blaster and the other relics, but his efforts proved unsuccessful as Solus Prime began to return. A concentrated attack by Primal, Grimlock and Windblade led to the Blaster and Enigma finally being released from the machine. Megatronus attempted to grab them, but was tackled by the heroes. From there, the Blaster began rapidly changing hands. Megatronus grabbed it and attempted to shoot the heroes, but was interrupted by the sudden arrival of Predaking. Megatron prepared to fire it at Solus, but was distracted when Megatronus threw Predaking's now-decapitated head. Finally, after Megatronus was destroyed, Optimal Optimus fired at Megatron, who sacrificed himself to ensure that the Matrix of Chaos would be destroyed in the process. In the aftermath, the Blaster was left in the care of Perceptor, who tasked himself with both studying and protecting the weapon.

Transformers: Universe
The Requiem Blaster is one of the most powerful weapon (first being the Star Saber) in Transformers: Universe.

Long ago, the Requiem Blaster was forged by Solus Prime to defeat Unicron. In the distant past, Megatronus destroyed Solus Prime with the Requiem Blaster. To prevent misuse, the remainder of the Thirteen took back the blaster and sealed it in a dome in Primal Swamp.

Many years later, the whereabouts of the Requiem Blaster had been lost to time. The Decepticons, led by Megatron, who splits himself into two using the power of Unicron - himself and Galvatron, search for the Blaster, using the Book of the Second Prophecies to determine that it was likely somewhere in Primal Swamp. Discovering a dome hidden in the swamp, he investigated and found the gun waiting inside, thought he also came face to face with a newly-revived Optimus Primal, who had been guarding the gun since. The two fought, but Primal surrendered the gun to Megatron, who eventually emerged with the Requiem Blaster in hand and used it to open fire on the Minnow.

Optimus Prime received visions of the future from the Matrix of Leadership, including one of the Blaster united with the Star Saber, the Matrix, the Apex Armor, the Enigma of Combination and the Forge of Solus Prime, though he knew not its meaning.