Star Saber (Prima)

Wielded by Prima, one of the original thirteen Transformers at the dawn of time, the Star Saber (sometimes spelled Star Sabre) sword was a weapon unlike any other. Though several other swords throughout the multiverse share its name, only one could snuff out stars and crumble the stuff of planets into dust. Many legends swirl around this blade of blades, from its origin to it its precise nature to the circumstances surrounding its disappearance into the annals of history, but somewhere between fiction and fact, the Star Saber waits to be discovered again by one worthy enough to wield its power...

Fun Publications comics
Long before recorded time began, Megatronus turned towards evil and began acting against his fellow siblings. To keep the all-powerful Star Saber from falling into evil hands, Nexus Prime decided to use his very body to conceal it. His fellow original Transformers Vector Prime, Alpha Trion, and Solus Prime agreed, and Solus Prime used her forge to smash the blade into five pieces. They then used the quantum edge of the blade (still functioning despite the sword's sad state), to carve Nexus himself into five pieces, each of which became an individual: Heatwave, Skyfall, Landquake, Topspin, and Breakaway. The five pieces of the Star Saber were then scattered across the multiverse, followed soon by the five components of Nexus Prime, their knowledge of the pieces' locations and of their own previous lives suppressed until such time as the sword was needed again. The blade's fragmented hilt, the Origin Matrix, was hidden on prehistoric Earth of Primax -408.24 Epsilon. Vector Prime then sealed the local spacetime in a time-lock so that no one could enter or exit. The Vok, already present to conduct one of their experiments, were entrusted with guarding the Matrix.

Uncounted aeons later, the components of Nexus Prime found each other once again, and the titan was re-formed. He proceeded to embark on a multiversal journey with the negative-polarity Quintesson Aquarius in order to recover the sword fragments, but one major obstacle stood in their way: Nexus Prime's memories had not returned entirely. He knew that he was searching for an artifact powerful enough to collapse the entire multiversal stack, but could no longer remember what the artifact was, what its pieces looked like, or where exactly they were. When the pair made a stop on the Cybertron of Primax 509.28 Epsilon, however, Nexus felt that the Cybertron Elite Guard symbol he spotted on a box was somehow a clue, one that finally got him started on the right track.

After unknown further adventures, Aquarius and Nexus succeeded in tracking down four of the five Star Saber fragments, with Aquarius picking up the fourth from a courier in Axiom Nexus. As payment, Aquarius then took the courier through a portal to her home dimension, but the pair were transferred by Nexus in-transit to Primax -408.24 Epsilon so that they could collect the fifth and final piece—the Origin Matrix, the gem from the blade's hilt—which had just been retrieved from its hiding place on the prehistoric Earth of that universe by Ultra Mammoth. Mammoth, however, asserted that he would personally hold onto the Matrix until Nexus Prime could come to collect it.

Later, as negative polarity Ultra Magnus was about to kill his positive polarity counterpart, Nexus Prime arrived, reformed the Star Saber with the Origin Matrix, and used it to slice Magnus's Terminus Blade-wielding arm cleanly off. The odds against him, Magnus attempted to escape, but Nexus simply used the Terminus Blade to open an interdimensional portal, exiling Magnus through it. Resolving to prevent multiversal crises such as that of Magnus's doing from ever happening again, Nexus Prime departed, traveling to a key point in interdimensional space. He then combined the powers of the Star Saber and the Terminus Blade together, strengthening the barriers between universes, rendering interdimensional travel nigh-impossible, and nullifying multiversal singularities.

Aligned novels
The Star Saber was one of the greatest weapons created by Solus Prime. To hide the full truth of its nature from any single Cybertronian, many myths exist about it; some claim that it was created out of three bots and wielded itself, others that it was integrated into the chassis of one of the Thirteen, and others still that Solus forged it from the core of a star, using its own heat as her furnace. More concretely, it is known that the Matrix of Leadership once adorned the sword's hilt.

According to Alpha Trion, the Star Saber was shattered into five pieces after the defeat of Liege Maximo. Per Trion's story, Nexus Prime gathered the pieces, broke himself into five bots—Clocker, Mainspring, Chaindrive, Pinion, and Cannonspring—hid a piece inside each bot, and spread his component bots across the universe in order to keep the Star Saber away from Megatronus.

Following the Great Exodus of Cybertronians from Cybertron, Optimus Prime was led across the galaxy by the Matrix of Leadership that he now bore, discovering on each stop blade-like fragments of Cybertronian metal. Optimus presumed them to be pieces of the Star Saber, but they were in actuality the Blades of Time, another artifact entrusted to Nexus. However, Prime's journey had also led to the discovery of the five components of Nexus Prime, who reformed during a battle with the Decepticons on Junkion. The sword he proceeded to summon was, contrary to legend, named the "Cyber Caliber", calling into question whether or not the story about him being guardian of the Star Saber was true.

Prime cartoon
The Star Saber was held in the Iacon vaults near the end of the war, and ejected into space with the rest of the items stored there. It found its way to Earth where it became entombed in rock. When Megatron uncovered it, he found that its energy rendered the rock around it indestructible and he was unable to extract it. The Decepticons attempted to lift the whole rock face with the Nemesis, but Optimus Prime was able to pull it from the stone. With it, he split the entire mountain in half and unleashed a wave of energy that struck the Nemesis. Alpha Trion later sent Optimus Prime a message using the sword.

Desperate to match Optimus' newfound power, Megatron transplanted the arm of a dead Prime onto himself, which allowed him to use the Forge of Solus Prime to forge the Dark Star Saber. He challenged Optimus to a battle for the latest relic, and though their swords seemed to be equal when it came to flinging energy waves around, the original Star Saber proved to be less durable when Megatron managed to shatter it with his own blade. The shards from the blade dissolved into dust, and Optimus took the hilt back to base with him.

After regaining the Forge of Solus Prime, Optimus used it to reforge the Star Saber and took it with him to Cybertron. He used it in battle with Megatron, matching the Dark Star Saber, and keeping his opposite busy while the other Autobots reclaimed the Omega Keys. Once they'd succeeded, he used the sword to knock Megatron flying so the Autobots could retreat.

With the Decepticons threatening the kids, Optimus had no choice but to throw down the Star Saber. When it turned out Megatron intended to destroy Earth, he picked up the sword again, using it to slice off Megatron's right arm and destroy the Omega Lock. He later used it to destroy the GroundBridge controls so the Decepticons couldn't work out where the Autobots had retreated to, though as moments later the Decepticons destroyed the base with Optimus and the sword still in it, the act was rendered moot. The Star Saber was pulled from the remains of the base by the Decepticons, and it was stored aboard the Nemesis.

When the Autobots assaulted the Nemesis, Smokescreen took the opportunity to retrieve the Star Saber. Bumblebee attempted to pass the weapon to Optimus, only to be blasted and killed by Megatron. The scout was subsequently restored by the power of the Omega Lock which the Decepticons had built into the starship, and he ran Megatron through with the Star Saber, ending the tyrant's life.

Optimus Prime used the Star Saber during the ceremony to make Bumblebee a warrior in a fashion similar to human knighting.

IDW Generation 1 continuity
According to the legends of Caminus the Star Saber was forged by Solus Prime and wielded by Prima with the Matrix of Leadership adorning its hilt. A statue of Prima within the Grand Imperium depicted him with the blade. Alpha Trion included the sword on a list of artifacts and weapons belonging to the Primes, along with the Enigma of Combination and the Onyx Triptych, that he considered unbeatable by 'ordinary' Cybertronians.

Transformers: Devastation
The Star Saber was one of the melee weapons that the Autobots could find in their quest to stop Megatron. It was usable by any of the Autobots.