Here's something for the TOTGA players. ...And anybody else, really. My trashy fanfiction is available for all audiences.
The Star Saber was originally going to be acquired a fair bit earlier in TOTGA's story. The circumstances through which the PCs would have gotten it would have played out much the same, with the difference being that the sword hadn't aged quite as well as one might have hoped. That would have given it a disadvantage in the ensuing duel against Nemesis Prime, and by the end of it, the Star Saber would have been destroyed.
That, then, would have served as additional motivation to go to Solus Prime's colony and find the Forge- it would have been the only thing capable of repairing the Star Saber. So after you guys restored the Astral Caminus, the PCs would have been "encouraged" to begin work on reforging the blade. The Heralds and their terrorcons would have shown up, naturally, and the PCs would've been forced to deal with them whilst the Star Saber was in the process of fixing itself it back up.
The kicker here is that the Star Saber would have still been usable during that process, gradually growing more powerful as whoever decided to wield it got more kills and the blade rebuilt itself little-by-little. Epic music'd play, Nemesis would've gotten his arm cut off, and so on.
Here are some mock-ups for how that might've gone down:
the introductory scene, meant to go with the first minute and ten seconds of Destiny 2's "Inner Light".
The Star Saber rested on the anvil, wreathed in curling tongues of steam and wisps of cosmic energy. The ancient metal shone like new, the edge of the blade glowing red-hot as the two shattered halves of the weapon pulled themselves together. Rivulets of liquid metal crept up and down the sword of Prima, filling in cracks and restoring the gold detailing in the hilt. Strings of Cyberglpyhs etched themselves along the blade, some of them glowing a faint blue. One could feel immense power radiating from the Star Saber: ancient, pure energies that defied science and resonated through the very fabric of the universe, and gave the legendary blade its awesome might. The broken sword could hardly contain it.
A horde of terrorcons charged at our heroes, screeching and howling, the purple aura of the Dark Energon coursing through their rusted bodies shining through the darkness. Such a force could overwhelm our heroes- tearing them apart and adding them to the ranks of Nemesis Prime's forces...
...But the Star Saber had been born anew, and even in its half-finished state, the sword of Warrior of Light remained the mightiest in the universe. It had felled legions of the undead in its time, sundered mountains and carved deep canyons in the metal flesh of Unicron himself. What, then, were a mere hundred undead?
The climax of the setpiece, in which the Star Saber would have been fully restored, and much terrorcon skidplate would have been kicked in the following moments.
The last jagged crack in the Star Saber's blade faded, and a tremendous, echoing sound like the tolling of great bell erupts from the weapon and carries across the field. The glyphs on the blade shine as white as the stars as the polished silver metal lights up with a piercing cyan aura. Terrorcons instinctively flinch, shielding their violet eyes from the light as crackling bolts of energy shoot out from the sword, striking the ground, the ancient machinery of the Caminus, and many an undead bot.
The Star Saber had now been restored to its full might, and even the simple minds of the terrorcons knew that it spelled doom for all but the strongest of villains...
This is one of those things that I wish I had done, honestly. To me, at least, it just seemed so much cooler looking back on it.